Made a new sketch on openprocessing.org to test for some different grade combinations quickly... but whenever I run it, the page freezes hangs until chrome says that it is unresponsive. My other sketches are working just fine, it is only this one.
Here is the sketch:
double a, o, u, k;
int[][] combos;
int[][] a_combos, b_combos;
int failcounter;
void setup() {
size(100,100);
background(100);
noLoop();
a = 2 + 4;
o = 4 + 4;
u = 3 + 4;
k = 3 + 5;
combos = new int[10000][4];
a_combos = new int[10000][4];
b_combos = new int[10000][4];
failcounter = 0;
}
void draw() {
fillCombos();
for (int i = 0; i < combos.length; i++) {
double atemp = a + combos[0];
double otemp = o + combos[1];
double utemp = u + combos[2];
double ktemp = k + combos[3];
double avg = (atemp + otemp + utemp + ktemp) / 4;
if (avg >= 17) {
a_combos[i] = combos[i];
} else if (avg >= 13.48) {
b_combos[i] = combos[i];
} else {
failcounter++;
}
}
println("Getting an A:");
for (int i = 0; i < a_combos.length; i++) {
if (a_combos[i] != null) println(a_combos[i]);
}
println("Getting a B:");
for (int i = 0; i < b_combos.length; i++) {
if (b_combos[i] != null) println(b_combos[i]);
}
println("A or B versus C, D, or F:");
println(10000 - failcount + ", " + failcount);
}
void fillCombos() {
int q = 0;
int w = 0;
int e = 0;
int r = 0;
for (int i = 0; i < combos.length; i++) {
combos[i][0] = q;
combos[i][1] = w;
combos[i][2] = e;
combos[i][3] = r;
r++;
if (r == 10) {
r = 0;
e++;
}
if (e == 10) {
e = 0;
w++;
}
if (w == 10) {
w = 0;
q++;
}
}
}
If I put print lines into several different locations in the code, none of them run for whatever reason. Any insight?
Related
I have implemented the algorithm according to this paper it's working well, but for certain tests, it doesn't get the shortest path,
here's the pseudo-code
Initialize
For t=1 to iteration number do
For k=1 to l do
Repeat until ant k has completed a tour
Select the city j to be visited next
With probability pij given by Eq. (1)
Calculate Lk
Update the trail levels according to Eqs. (2-4).
End
here's the code
import java.io.*;
import java.util.*;
import static java.lang.Math.*;
public class test2 {
private InputReader cin;
private PrintWriter cout;
double pheromones[][];
double distances[][];
double visibility[][];
static int n;
City[] city;
Ant[] ant;
int m;
int T;
double alpha = 1; // pheromone importance
double beta = 2; // visibility importance
double evaporation = 0.1;
double Q = 100.0;
static class City {
double x, y;
int id;
public City(double x, double y, int id) {
this.x = x;
this.y = y;
this.id = id;
}
}
static class Ant {
int whereAmI;
boolean[] visited;
double tourDistance;
LinkedList<Integer> citiesVisitedInOrder;
int cityEdges[][];
Ant(int whereAmI) {
this.whereAmI = whereAmI;
visited = new boolean[n + 1];
cityEdges = new int[n + 1][n + 1];
reset();
}
void reset() {
Arrays.fill(visited, false);
visited[whereAmI] = true;
for (int i = 1; i <= n; i++)
Arrays.fill(cityEdges[i], 0);
tourDistance = 0;
citiesVisitedInOrder = new LinkedList<>();
citiesVisitedInOrder.addLast(whereAmI);
}
}
//the actual algorithm iteration
/*
Initialize
For t=1 to iteration number do
For k=1 to l do
Repeat until ant k has completed a tour
Select the city j to be visited next
With probability pij given by Eq. (1)
Calculate Lk
Update the trail levels according to Eqs. (2-4).
End
*/
private void solve() {
n = cin.readInt();
initializeParameter();
//the main loop
for (int t = 0; t < T; t++) {
for (int i = 0; i < m; i++) {//for each ant
Ant current = ant[i];
for (int j = 0; j < n; j++) {//for each city
int currentAntsCity = current.whereAmI;
double highestProbability = 0;
int cityId = 1;
double sumNotiation = calculateSum(current.visited, currentAntsCity);
//traverse all non-visited cities and choose the best
boolean good = false;
for (int c = 1; c <= n; c++) {//remove the equal
if (!current.visited[c]) {
double prop = (pow(pheromones[currentAntsCity][c], alpha) * pow(visibility[currentAntsCity][c], beta))
/ sumNotiation;
if (prop >= highestProbability) {
highestProbability = prop;
cityId = c;
good = true;
}
}
}
if (good) {
current.tourDistance += distances[currentAntsCity][cityId];
current.cityEdges[currentAntsCity][cityId] = current.cityEdges[cityId][currentAntsCity] = 1;
current.citiesVisitedInOrder.addLast(cityId);
current.whereAmI = cityId;
current.visited[cityId] = true;
}
}//after n iteration i ant completes a tour
current.tourDistance += distances[current.citiesVisitedInOrder.getFirst()][current.citiesVisitedInOrder.getLast()];
}//update
for (int i = 1; i <= n; i++) {
for (int j = i + 1; j <= n; j++) {
double deltaPhermons = 0;
for (int a = 0; a < m; a++) {
if (ant[a].cityEdges[i][j] != 0) {
deltaPhermons += Q / ant[a].tourDistance;
}
}
pheromones[i][j] = pheromones[j][i] = pheromones[i][j] * evaporation + deltaPhermons;
pheromones[i][i] = 0;
}
}
if (t == T - 1)
break;
//reset everything
for (int i = 0; i < m; i++) {
ant[i].reset();
}
}
//get the best ant route
double minDistance = Double.MAX_VALUE;
LinkedList<Integer> minRout = new LinkedList<>();
for (Ant ant : ant) {
if (ant.tourDistance < minDistance) {
minDistance = ant.tourDistance;
minRout = ant.citiesVisitedInOrder;
}
}
cout.println(minDistance);
for (int element : minRout)
cout.print(element + " ");
}
private double calculateSum(boolean[] visited, int currentAntsCity) {
//traverse all non-visited cities
double ans = 0.0;
for (int c = 1; c <= n; c++) {
if (!visited[c]) {
ans +=
pow(pheromones[currentAntsCity][c], alpha) *
pow(visibility[currentAntsCity][c], beta);
}
}
return ans;
}
private void initializeParameter() {
m = 2 * n;
T = 4 * m;
city = new City[n + 1];
pheromones = new double[n + 1][n + 1];
distances = new double[n + 1][n + 1];
visibility = new double[n + 1][n + 1];
//read cities coordinates
for (int i = 1; i <= n; i++) {
city[i] = new City(cin.readDouble(), cin.readDouble(), i);
}
//initialize distances
for (int i = 1; i <= n; i++) {
for (int j = i + 1; j <= n; j++) {
distances[i][j] = distances[j][i] = sqrt(pow(city[i].x -
city[j].x, 2.0) + pow(city[i].y -
city[j].y, 2.0));
}
}
//initialize the pheromones
double pheromones0 = 1.0 / (double) n;
for (int i = 1; i <= n; i++) {
Arrays.fill(pheromones[i], pheromones0);
pheromones[i][i] = 0;
}
//initialize the visibility
for (int i = 1; i <= n; i++) {
for (int j = i + 1; j <= n; j++) {
visibility[i][j] = visibility[j][i] = 1.0 / distances[i][j];
}
}
//initialize the ants
ant = new Ant[m];
Random rand = new Random(); //instance of random class for
for (int i = 0; i < m; i++) {
int random_int = rand.nextInt(n) + 1;
ant[i] = new Ant(random_int);
}
}
public static void main(String args[]) {
new test2().run();
}
private void run() {
// cin = new InputReader(System.in);
// cout = new PrintWriter(System.out);
try {
cin = new InputReader(new FileInputStream("input.txt"));
cout = new PrintWriter(new FileOutputStream("output.txt"));
} catch (FileNotFoundException e) {
//System.out.println(e.toString());
}
solve();
cout.close();
}
//just for faster reading from a file
public static class InputReader {
private InputStream stream;
private byte[] buf = new byte[1024];
private int curChar, numChars;
public InputReader(InputStream stream) {
this.stream = stream;
}
public int read() {
if (numChars == -1)
throw new InputMismatchException();
if (curChar >= numChars) {
curChar = 0;
try {
numChars = stream.read(buf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (numChars <= 0)
return -1;
}
return buf[curChar++];
}
public int readInt() {
int c = read();
while (isSpaceChar(c))
c = read();
int sgn = 1;
if (c == '-') {
sgn = -1;
c = read();
}
int res = 0;
do {
if (c < '0' || c > '9')
throw new InputMismatchException();
res *= 10;
res += c - '0';
c = read();
} while (!isSpaceChar(c));
return res * sgn;
}
public double readDouble() {
int c = read();
while (isSpaceChar(c))
c = read();
int sgn = 1;
if (c == '-') {
sgn = -1;
c = read();
}
double res = 0;
while (!isSpaceChar(c) && c != '.') {
if (c == 'e' || c == 'E')
return res * pow(10, readInt());
if (c < '0' || c > '9')
throw new InputMismatchException();
res *= 10;
res += c - '0';
c = read();
}
if (c == '.') {
c = read();
double m = 1;
while (!isSpaceChar(c)) {
if (c == 'e' || c == 'E')
return res * pow(10, readInt());
if (c < '0' || c > '9')
throw new InputMismatchException();
m /= 10;
res += (c - '0') * m;
c = read();
}
}
return res * sgn;
}
private boolean isSpaceChar(int c) {
return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
}
}
}
the test case
10
-15 89
-5 -49
-35 -18
7 49
-95 -68
85 -39
53 -1
69 -99
-74 8
-52 -35
the right answer:
615.11811789868988853
1 9 5 10 3 2 8 6 7 4
my coes's output:
685.2134200307595
5 9 10 3 2 8 6 7 4 1
as you can notice I am not getting the shortest path, I believe that the mistake is somewhere in the constant, and the probability comparing!
the formula I have implemented
and the update formulas
how can I improve the algorithm accuracy? or maybe there's something wrong in my implementation!
I found the solution, Changing the Update functions after each complete tour for all ants, fixed the problem:
#part 1
//the elaboration presses after a complete tour for all ants
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
pheromones[i][j] *= evaporation;
if (pheromones[i][j] < 1.0 / (double) n)//notice it the phermones can't be less than the starting value`
pheromones[i][j] = 1.0 / (double) n;
pheromones[i][i] = 0;
}
}
#part 2
//update the phermonses
for (int i = 0; i < m; i++) {
for (int j = i + 1; j <= n; j++) {
int from = ant[i].rout[0];
int to = ant[i].rout[n - 1];
pheromones[from][to] += Q / ant[i].tourDistance;
pheromones[to][from] = pheromones[from][to];
}
}
source HERE
strangely enough the algorithm can work without the elaboration presses i.e. #part1.
Anyway here's the complete code with little changes
import java.io.*;
import java.util.*;
import static java.lang.Math.*;
public class test2 {
private InputReader cin;
private PrintWriter cout;
double[][] arr;
double[][] pheromones;
double[][] distances;
double[][] visibility;
static int n;
Ant[] ant;
int m;
int T;
double alpha = 1; // pheromone importance
double beta = 3; // visibility importance
double evaporation = 0.9;
double Q = 40.0;
double pheromones0;
static class Ant {
int whereAmI;
boolean[] visited;
double tourDistance;
private int ctr; //counter for the cites thought which the ant pass
private int[] route;
Ant(int whereAmI) {
this.whereAmI = whereAmI;
reset();
}
void reset() {
ctr = 0;
route = new int[n];
visited = new boolean[n + 1];
visited[whereAmI] = true;
tourDistance = 0;
addCityToTheRoute(whereAmI);
}
void addCityToTheRoute(int cityId) {
route[ctr++] = cityId;
}
}
private void solve() {
n = cin.readInt();
initializeParameter();
double mi = Double.MAX_VALUE;
int[] cityRoute = new int[n];
//the main loop
for (int t = 0; t < T; t++) {
for (int i = 0; i < m; i++) {//for each ant
for (int j = 0; j < n; j++) {//for each city
double highestProbability = 0;
int cityId = 1;
double sumNotiation = calculateSum(ant[i].visited, ant[i].whereAmI);
//traverse all non-visited cities and choose the best
boolean good = false;
for (int c = 1; c <= n; c++) {//remove the equal
if (!ant[i].visited[c]) {
double prop = (pow(pheromones[ant[i].whereAmI][c], alpha) * pow(visibility[ant[i].whereAmI][c], beta))
/ sumNotiation;
if (prop >= highestProbability) {
highestProbability = prop;
cityId = c;
good = true;
}
}
}
if (good) {
ant[i].tourDistance += distances[ant[i].whereAmI][cityId];
ant[i].addCityToTheRoute(cityId);
ant[i].whereAmI = cityId;
ant[i].visited[cityId] = true;
}
}//after n iteration i ant completes a tour
ant[i].tourDistance += distances[ant[i].route[0]][ant[i].route[n - 1]];//add the distance from the last city to the first city
//while k ant finishes its tour take the best ant's route so far
if (ant[i].tourDistance < mi) {
mi = ant[i].tourDistance;
cityRoute = ant[i].route;
}
}
//update
//evaporatePheromones
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
pheromones[i][j] *= evaporation;
if (pheromones[i][j] < pheromones0)
pheromones[i][j] = pheromones0;
pheromones[i][i] = 0;
}
}
//updatePheromones
for (int i = 0; i < m; i++) {
for (int j = i + 1; j <= n; j++) {
int from = ant[i].route[0];
int to = ant[i].route[n - 1];
pheromones[from][to] += Q / ant[i].tourDistance;
pheromones[to][from] = pheromones[from][to];
}
}
if (t == T - 1)
break;
//reset everything
for (int i = 0; i < m; i++) {
ant[i].reset();
}
}
//print the route with the distance
cout.println(mi);
for (int element : cityRoute)
cout.print(element + " ");
}
private double calculateSum(boolean[] visited, int currentAntsCity) {
//traverse all non-visited cities
double ans = 0.0;
for (int c = 1; c <= n; c++) {
if (!visited[c]) {
ans +=
pow(pheromones[currentAntsCity][c], alpha) *
pow(visibility[currentAntsCity][c], beta);
}
}
return ans;
}
private void initializeParameter() {
m = 20 * n;
T = 20;
pheromones = new double[n + 1][n + 1];
distances = new double[n + 1][n + 1];
visibility = new double[n + 1][n + 1];
//read cities coordinates
arr = new double[n + 1][2];
for (int i = 1; i <= n; i++) {
double x = cin.readDouble();
double y = cin.readDouble();
arr[i][0] = x;
arr[i][1] = y;
}
//initialize distances
for (int i = 1; i <= n; i++) {
for (int j = i + 1; j <= n; j++) {
distances[i][j] = distances[j][i] = sqrt(pow(arr[i][0] -
arr[j][0], 2.0) + pow(arr[i][1] -
arr[j][1], 2.0));
}
}
//initialize the pheromones
pheromones0 = 1.0 / (double) n;
for (int i = 1; i <= n; i++) {
Arrays.fill(pheromones[i], pheromones0);
pheromones[i][i] = 0;
}
//initialize the visibility
for (int i = 1; i <= n; i++) {
for (int j = i + 1; j <= n; j++) {
visibility[i][j] = visibility[j][i] = 1.0 / distances[i][j];
}
}
//initialize the ants
ant = new Ant[m];
Random rand = new Random(); //instance of random class for
for (int i = 0; i < m; i++) {
int random_int = rand.nextInt(n) + 1;
ant[i] = new Ant(random_int);
}
}
public static void main(String args[]) {
new test2().run();
}
private void run() {
// cin = new InputReader(System.in);
// cout = new PrintWriter(System.out);
try {
cin = new InputReader(new FileInputStream("input.txt"));
cout = new PrintWriter(new FileOutputStream("output.txt"));
} catch (FileNotFoundException e) {
//System.out.println(e.toString());
}
solve();
cout.close();
}
//just for faster reading from a file
public static class InputReader {
private InputStream stream;
private byte[] buf = new byte[1024];
private int curChar, numChars;
public InputReader(InputStream stream) {
this.stream = stream;
}
public int read() {
if (numChars == -1)
throw new InputMismatchException();
if (curChar >= numChars) {
curChar = 0;
try {
numChars = stream.read(buf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (numChars <= 0)
return -1;
}
return buf[curChar++];
}
public int readInt() {
int c = read();
while (isSpaceChar(c))
c = read();
int sgn = 1;
if (c == '-') {
sgn = -1;
c = read();
}
int res = 0;
do {
if (c < '0' || c > '9')
throw new InputMismatchException();
res *= 10;
res += c - '0';
c = read();
} while (!isSpaceChar(c));
return res * sgn;
}
public double readDouble() {
int c = read();
while (isSpaceChar(c))
c = read();
int sgn = 1;
if (c == '-') {
sgn = -1;
c = read();
}
double res = 0;
while (!isSpaceChar(c) && c != '.') {
if (c == 'e' || c == 'E')
return res * pow(10, readInt());
if (c < '0' || c > '9')
throw new InputMismatchException();
res *= 10;
res += c - '0';
c = read();
}
if (c == '.') {
c = read();
double m = 1;
while (!isSpaceChar(c)) {
if (c == 'e' || c == 'E')
return res * pow(10, readInt());
if (c < '0' || c > '9')
throw new InputMismatchException();
m /= 10;
res += (c - '0') * m;
c = read();
}
}
return res * sgn;
}
private boolean isSpaceChar(int c) {
return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
}
}
}
I have implemented a solutions for multiplying any two large numbers, the solution I am getting seems to be working fine for many inputs however when I pass
"3141592653589793238462643383279502884197169399375105820974944592"
"2718281828459045235360287471352662497757247093699959574966967627"
It's not giving correct answer
I am using Basic Java Syntax
import java.util.*;
public class GenericOperations {
static String addTwoLargeNumber(String X, String Y)
{
String Z = "";
int i = X.length() - 1;
int j = Y.length() - 1;
int carry = 0;
while(i>-1 && j>-1)
{
int digitSum = Character.getNumericValue(X.charAt(i)) +
Character.getNumericValue(Y.charAt(j)) + carry;
if(digitSum > 9)
{
Z = digitSum%10 + Z;
carry=1;
}
else
{
Z = digitSum + Z;
carry = 0;
}
i--;j--;
}
while(i>-1)
{
int digitSum = Character.getNumericValue(X.charAt(i)) + carry;
if(digitSum > 9)
{
Z = digitSum%10 + Z;
carry=1;
}
else
{
Z = digitSum + Z;
carry = 0;
}
i--;
}
while(j>-1)
{
int digitSum = Character.getNumericValue(Y.charAt(j)) + carry;
if(digitSum > 9)
{
Z = digitSum%10 + Z;
carry=1;
}
else
{
Z = digitSum + Z ;
carry = 0;
}
j--;
}
return Z;
}
static String multiplyTwoLargeNumbers(String X, String Y)
{
ArrayList<String> additionList = new ArrayList<String>();
ArrayList<String> additionListWithZeros = new ArrayList<String>();
int n = X.length() - 1;
int m = Y.length() - 1 ;
int carry = 0;
int i=0,j=0;
for(i=n ; i>-1; i--)
{
carry = 0;
String Z = "";
for(j = m ; j>-1 ; j--)
{
int digitSum = ( Character.getNumericValue(X.charAt(i)) *
Character.getNumericValue(Y.charAt(j)) )
+ carry;
if(digitSum > 9)
{
Z = digitSum%10 + Z;
carry= digitSum/10;
}
else
{
Z = digitSum + Z;
carry = 0;
}
}
if(carry!=0)
{
Z = carry + Z;
}
additionList.add(Z);
}
int k = 0;
String sum = "";
for (Iterator<String> iterator = additionList.iterator(); iterator.hasNext();)
{
String val1 = iterator.next();
for(int x = 0;x<k;x++)
{
val1 = val1 + 0;
}
k++;
//System.out.println(val1);
sum = addTwoLargeNumber(sum,val1);
}
return sum;
}
static void printArray(int arr[])
{
int n = arr.length;
for (int i=0; i<n; ++i)
{
System.out.print(arr[i] + " ");
}
System.out.println();
}
public static void main(String args[])
{
String val = multiplyTwoLargeNumbers(
"3141592653589793238462643383279502884197169399375105820974944592",
"2718281828459045235360287471352662497757247093699959574966967627");
System.out.println(val);
}
}
Expected Result:
8539734222673567065463550869546574495034888535765114961879601127067743044893204848617875072216249073013374895871952806582723184
Actual Results:
8539734222673566965463549869546574495034887534765114961879601127067743044893204848617875072216249073013374895871952806582723184
You just missed a carry when adding.
Add following and you should be done:
if (carry != 0) {
Z = carry + Z;
}
BTW: simplified the addTwoLargeNumber-method
static String addTwoLargeNumber(String X, String Y) {
String Z = "";
int maxPos = Math.max(X.length(), Y.length());
int carry = 0;
for (int pos = 0; pos < maxPos; pos++) {
final int currValX
= pos < X.length()
? Character.getNumericValue(X.charAt(X.length() - 1 - pos)) : 0;
final int currValY
= pos < Y.length()
? Character.getNumericValue(Y.charAt(Y.length() - 1 - pos)) : 0;
int digitSum = currValX + currValY + carry;
Z = digitSum % 10 + Z;
carry = digitSum / 10;
}
if (carry != 0) {
Z = carry + Z;
}
return Z;
}
I'm trying to do the Algorithm programming assignment of Princeton , and I met a problem about the memory test. The assignment requires us run the percolation program N times and find the medium of the result, and I write a percolationtest.java and for each time, I create an instance variable, it worked, but use too much memory, and the instructor suggests me to use local variable, but I don't know how. Can some one help me and give me some advice, I really appreciate it.
public class PercolationStats {
private int N, T, totalSum;
private double []fraction;
private int []count;
public PercolationStats(int N, int T) {
if (N <= 0 || T <= 0)
throw new IllegalArgumentException();
else {
this.N = N;
this.T = T;
count = new int [T];
totalSum = N*N;
fraction = new double[T];
int randomX, randomY;
for (int i = 0; i < T; i++) {
Percolation perc = new Percolation(N);
while (true) {
if (perc.percolates()) {
fraction[i] = (double) count[i]/totalSum;
break;
}
randomX = StdRandom.uniform(1, N+1);
randomY = StdRandom.uniform(1, N+1);
if (perc.isOpen(randomX, randomY)) continue;
else {
perc.open(randomX, randomY);
count[i]++;
}
}
}
}
} // perform T independent experiments on an N-by-N grid
public double mean() {
double totalFraction = 0;
for (int i = 0; i < T; i++) {
totalFraction += fraction[i];
}
return totalFraction/T;
} // sample mean of percolation threshold
public double stddev() {
double u = this.mean();
double sum = 0;
for (int i = 0; i < T; i++) {
sum += (fraction[i] - u) * (fraction[i] - u);
}
return Math.sqrt(sum/(T-1));
} // sample standard deviation of percolation threshold
public double confidenceLo() {
double u = this.mean();
double theta = this.stddev();
double sqrtT = Math.sqrt(T);
return u-1.96*theta/sqrtT;
} // low endpoint of 95% confidence interval
public double confidenceHi() {
double u = this.mean();
double theta = this.stddev();
double sqrtT = Math.sqrt(T);
return u+1.96*theta/sqrtT;
} // high endpoint of 95% confidence interval
public static void main(String[] args) {
int N = 200;
int T = 100;
if (args.length == 1) N = Integer.parseInt(args[0]);
else if (args.length == 2) {
N = Integer.parseInt(args[0]);
T = Integer.parseInt(args[1]); }
PercolationStats a = new PercolationStats(N, T);
System.out.print("mean = ");
System.out.println(a.mean());
System.out.print("stddev = ");
System.out.println(a.stddev());
System.out.print("95% confidence interval = ");
System.out.print(a.confidenceLo());
System.out.print(", ");
System.out.println(a.confidenceHi());
}
}
public class Percolation {
private boolean[][] site;
private WeightedQuickUnionUF uf;
private int N;
public Percolation(int N) {
if (N < 1)
throw new IllegalArgumentException();
else {
site = new boolean[N + 2][N + 2];
for (int j = 1; j <= N; j++) {
site[0][j] = true;
site[N + 1][j] = true;
}
uf = new WeightedQuickUnionUF((N + 2) * (N + 2));
for (int i = 1; i <= N; i++) {
uf.union(0, i);
}
this.N = N;
}
}
public void open(int i, int j) {
if (i > N || i < 1 || j > N || j < 1)
throw new IndexOutOfBoundsException();
else {
if (!site[i][j]) {
site[i][j] = true;
if (site[i - 1][j]) {
uf.union((N + 2) * (i - 1) + j, (N + 2) * i + j);
}
if (site[i + 1][j]) {
uf.union((N + 2) * i + j, (N + 2) * (i + 1) + j);
}
if (site[i][j + 1]) {
uf.union((N + 2) * i + (j + 1), (N + 2) * i + j);
}
if (site[i][j - 1]) {
uf.union((N + 2) * i + (j - 1), (N + 2) * i + j);
}
}
}
}
public boolean isOpen(int i, int j) {
if (i > N || i < 1 || j > N || j < 1)
throw new IndexOutOfBoundsException();
else
return site[i][j];
}
public boolean isFull(int i, int j) {
if (i > N || i < 1 || j > N || j < 1)
throw new IndexOutOfBoundsException();
else
return site[i][j] && (i == 1 || uf.connected((N + 2) * i + j, 0));
}
public boolean percolates() {
for (int i = 1; i <= N; i++) {
if (this.isFull(N, i)) {
return true;
}
}
return false;
}
public static void main(String[] args) {
}
}
Added meanValue instance variable to keep mean value and replaced it in multiple places where you used to call mean() method which was over head to calculate again and again. Also modified "int[] count" as local variable which you were not using outside the constructor. post your "Percolation" and "StdRandom" classes for more optimization of code. you can run this code and test, it should reduce the runtime than yours.
public class PercolationStats {
private int N, T, totalSum;
private double []fraction;
private double meanValue;
public PercolationStats(int N, int T) {
if (N <= 0 || T <= 0)
throw new IllegalArgumentException();
else {
this.N = N;
this.T = T;
int [] count = new int [T];
totalSum = N*N;
fraction = new double[T];
int randomX, randomY;
for (int i = 0; i < T; i++) {
Percolation perc = new Percolation(N);
while (true) {
if (perc.percolates()) {
fraction[i] = (double) count[i]/totalSum;
break;
}
randomX = StdRandom.uniform(1, N+1);
randomY = StdRandom.uniform(1, N+1);
if (perc.isOpen(randomX, randomY)) continue;
else {
perc.open(randomX, randomY);
count[i]++;
}
}
}
}
}
// perform T independent experiments on an N-by-N grid
public double mean() {
double totalFraction = 0;
for (int i = 0; i < T; i++) {
totalFraction += fraction[i];
}
meanValue = totalFraction/T;
return meanValue;
} // sample mean of percolation threshold
public double stddev() {
double u = meanValue;
double sum = 0;
for (int i = 0; i < T; i++) {
sum += (fraction[i] - u) * (fraction[i] - u);
}
return Math.sqrt(sum/(T-1));
} // sample standard deviation of percolation threshold
public double confidenceLo() {
double u = meanValue;
double theta = this.stddev();
double sqrtT = Math.sqrt(T);
return u-1.96*theta/sqrtT;
} // low endpoint of 95% confidence interval
public double confidenceHi() {
double u = meanValue;
double theta = this.stddev();
double sqrtT = Math.sqrt(T);
return u+1.96*theta/sqrtT;
} // high endpoint of 95% confidence interval
public static void main(String[] args) {
int N = 200;
int T = 100;
if (args.length == 1) N = Integer.parseInt(args[0]);
else if (args.length == 2) {
N = Integer.parseInt(args[0]);
T = Integer.parseInt(args[1]); }
PercolationStats a = new PercolationStats(N, T);
System.out.print("mean = ");
System.out.println(a.mean());
System.out.print("stddev = ");
System.out.println(a.stddev());
System.out.print("95% confidence interval = ");
System.out.print(a.confidenceLo());
System.out.print(", ");
System.out.println(a.confidenceHi());
}
}
What I need is a little modification to my code so that every part of my hollow diamond prints a letter of the word "HURRICANE"
My code is:
String st1 = "HURRICANE";
int a = 0;
for (int i = 5; i >= 1; i--) {
for (int j = 1; j <= 9; j++) {
if (j == i || (10 - i) == j) {
System.out.print(st1.charAt(a)); //needs change
} else {
System.out.print(' ');
}
}
System.out.println();
}
for (int i = 2; i <= 5; i++) {
for (int j = 1; j <= 9; j++) {
if (j == i || (10 - i) == j) {
System.out.print(st1.charAt(a)); //needs change
} else {
System.out.print(' ');
}
}
System.out.println();
}
The output comes out as:
H
H H
H H
H H
H H
H H
H H
H H
H
I need to modify my "charAt" statement a little so it comes out to be:
H
U U
R R
R R
I I
C C
A A
N N
E
How should I make my print statement?
It's worth noting that the example provided only works for Strings the same length as "HURRICANE". A superior solution would work for all strings.
Partial solution for you to complete, since I guess it's your coursework and I don't want you to copy / paste / fail exams :P
public static void main(String[] args) {
String st1 = "HURRICANE";
char[] st1CharArray = st1.toCharArray();
int maxSpaces = st1CharArray.length / 2 + 1;
for (int i = 0; i <= st1CharArray.length / 2; i++) {
if (i == 0) {
System.out.println(getSpacesString(maxSpaces) + st1CharArray[i]);
} else {
System.out.println(getSpacesString(maxSpaces - i)
+ st1CharArray[i] + getSpacesString(i * 2 - 1)
+ st1CharArray[i]);
}
}
// Loop from st1CharArray.length / 2 + 1 and get the second half done.
}
private static String getSpacesString(int numberOfSpaces) {
StringBuilder strBuilder = new StringBuilder();
for (int i = 0; i < numberOfSpaces; i++) {
strBuilder.append(" ");
}
return strBuilder.toString();
}
//: Playground - noun: a place where people can play
import UIKit
var name : String = "HURRICANE"
var dimensions : Int = name.count - 1
var k : Int = 0
for rows in 0...dimensions{
for columns in 0...dimensions{
k = abs( (dimensions/2) - rows )
if columns == k || columns == dimensions - k{
print(Array(name)[rows], terminator: "")
}
else{
print(" ", terminator: "" )
}
}
print("")
}
String st1 = "HURRICANE";
int a = 0;
for (int i = 5; i >= 1; i--) {
for (int j = 1; j <= 9; j++) {
if (j == i || (10 - i) == j) {
System.out.print(st1.charAt(5 - i));
} else {
System.out.print(' ');
}
}
System.out.println();
}
for (int i = 2; i <= 5; i++) {
for (int j = 1; j <= 9; j++) {
if (j == i || (10 - i) == j) {
System.out.print(st1.charAt(3 + i));
} else {
System.out.print(' ');
}
}
System.out.println();
}
Let's assume that a word has an odd number of characters, otherwise we get a crooked diamond.
Try it online!
public static void main(String[] args) {
String str = "abrahadabra";
int n = str.length() / 2;
for (int i = -n, ch = 0; i <= n && ch < str.length(); i++, ch++) {
for (int j = -n; j <= n; j++)
if (Math.abs(i) + Math.abs(j) == n)
System.out.print(str.charAt(ch));
else
System.out.print(" ");
System.out.println();
}
}
Output:
a
b b
r r
a a
h h
a a
d d
a a
b b
r r
a
Hi below is my program which displays top 10 frequently occuring words but my requirement is to get top 30 frequently occuring words,
class FrequencyCount {
int[][] table = new int[4][1000000];
TreeMap<Integer, List<String>> map = new TreeMap<Integer, List<String>>(
Collections.reverseOrder());
public static void main(String[] args) throws Exception {
FrequencyCount freq = new FrequencyCount();
BufferedReader br = null;
try {
br = new BufferedReader(new FileReader(new File(
"C:/portable.pdf")));
String fileline = br.readLine();
System.out.println("fileline:" + fileline);
while (fileline != null) {
if (fileline.length() > 0) {
String[] sArr = fileline.split(" ");
for (String s : sArr) {
int flag = 1;
for (int j = 0; j < stopwords.length; j++) {
String s1 = s.toLowerCase();
}
if (flag != 0) {
if (s.trim().length() > 0) {
try {
freq.add(freq.trimStr(s));
} catch (ArrayIndexOutOfBoundsException e) {
}
}
}
}
}
fileline = br.readLine();
}
Set<Integer> set = freq.map.keySet();
for (Integer x : set) {
System.out.println(freq.map.get(x) + " found " + x + " times");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
br.close();
}
}
public String trimStr(String s) {
if (s.toUpperCase().equals(s.toLowerCase())) {
return s;
}
s = s.toLowerCase().trim();
if (s.endsWith("'s")) {
s = s.substring(0, s.length() - 2);
}
int i = 0;
int j = s.length() - 1;
char[] cArr = s.toCharArray();
while (!(cArr[i] >= 65 && cArr[i] <= 90)
&& !(cArr[i] >= 97 && cArr[i] <= 122)) {
i++;
}
while (!(cArr[j] >= 65 && cArr[j] <= 90)
&& !(cArr[j] >= 97 && cArr[j] <= 122)) {
j--;
}
return s.substring(i, j + 1);
}
public int[] hash(String s) {
int h1 = hash1(s);
int h2 = hash2(s);
int h3 = hash3(s);
int h4 = hash4(s);
int[] res = new int[] { h1, h2, h3, h4 };
return res;
}
public int hash1(String x) {
char ch[] = x.toCharArray();
int i, sum;
for (sum = 0, i = 0; i < x.length(); i++)
sum += ch[i];
return sum % 1000000;
}
public int hash2(String s) {
int h = 0;
for (int i = 0; i < s.length(); i++) {
h = 31 * h + s.charAt(i);
}
h = h % 1000000;
if (h < 0) {
h = -h;
}
return h;
}
public int hash3(String s) {
int h = 0;
for (int i = 0; i < s.length(); i++) {
h = 17 * h + s.charAt(i);
}
h = h % 1000000;
if (h < 0) {
h = -h;
}
return h;
}
public int hash4(String s) {
int h = 0;
for (int i = 0; i < s.length(); i++) {
h = 11 * h + s.charAt(i);
}
h = h % 1000000;
if (h < 0) {
h = -h;
}
return h;
}
public void add(String s) {
int[] h = hash(s);
table[0][h[0]] = table[0][h[0]] + 1;
table[1][h[1]] = table[1][h[1]] + 1;
table[2][h[2]] = table[2][h[2]] + 1;
table[3][h[3]] = table[3][h[3]] + 1;
int r = Math.min(Math.min(Math.min(table[0][h[0]], table[1][h[1]]),
table[2][h[2]]), table[3][h[3]]);
boolean add = true;
List<String> list = map.get(r);
if (list == null) {
if (map.size() == 10) {
Integer lastKey = map.lastKey();
if (lastKey.intValue() > r) {
add = false;
} else {
map.remove(lastKey);
}
}
list = new ArrayList<String>();
}
if (add) {
list.add(s);
map.put(r, list);
if (r > 1) {
list = map.get(r - 1);
if (list != null) {
if (list.size() == 1) {
map.remove(r - 1);
} else {
list.remove(s);
}
}
}
}
}
public int count(String s) {
int[] h = hash(s);
int a = table[0][h[0]];
int b = table[1][h[1]];
int c = table[2][h[2]];
int d = table[3][h[3]];
int r = Math.min(Math.min(Math.min(a, b), c), d);
return r;
}
}
I have changed the map size to 30, but its not working, please suggest me how to get top 30 frequently occurring words.
Thanks
I would use a different approach. I would add store the word in a HashMap instead and use the string in lowercase as key and then number of time it occured as the value. When the entire map is created you can sort it as described here and display any number from the top as you like.
The general idea:
HashMap<String, Integer> wordcounter = new HashMap<String, Integer>();
if (wordcounter.containsKey(s))
wordcounter.put(s, wordcounter.get(s) + 1);
else
wordcounter.put(s, 1);
There is only one word change from 10 to 30 as mentioned below.
public void add(String s) {
int[] h = hash(s);
table[0][h[0]] = table[0][h[0]] + 1;
table[1][h[1]] = table[1][h[1]] + 1;
table[2][h[2]] = table[2][h[2]] + 1;
table[3][h[3]] = table[3][h[3]] + 1;
int r = Math.min(Math.min(Math.min(table[0][h[0]], table[1][h[1]]),
table[2][h[2]]), table[3][h[3]]);
boolean add = true;
List<String> list = map.get(r);
if (list == null) {
if (map.size() == 30) {//Changed from 10 to 30
Integer lastKey = map.lastKey();
if (lastKey.intValue() > r) {
add = false;
} else {
map.remove(lastKey);
}
}
list = new ArrayList<String>();
}
if (add) {
list.add(s);
map.put(r, list);
if (r > 1) {
list = map.get(r - 1);
if (list != null) {
if (list.size() == 1) {
map.remove(r - 1);
} else {
list.remove(s);
}
}
}
}
}