I'm trying to print out the numbers that are below a specific number entered as a command line argument (e.g 430) that contain specific digits (e.g 2 and 3).
So that my program prints only numbers containing 2 and 3 and are below 430, so the answer would be : 2,3,23,32, etc.
I've written a piece of code but for some reason I can't get it to work.
Any help is appreciated !
Here's my code:
public static void main(String[] args) {
int input = Integer.parseInt(args[0]);
for(int i=0; i<input; i++) {
String test= Integer.toString(i);
for(int j=0; j<test.length(); j++) {
if((test.charAt(j) != '2') || (test.charAt(j)!='3')) {
}
else {
System.out.println("The digit is " + i);
}
}
}
}
You'll never reach the else block.
if((test.charAt(j) != '0')
|| (test.charAt(j)!='1')) {
}
Should be:
if((test.charAt(j) != '0')
&& (test.charAt(j)!='1')) {
}
Here is working code. In your code, why are you checking for 0 and 1 instead of 2 and 3.
public static void main(String[] args) {
int input = Integer.parseInt(args[0]);
int two = 0, three = 0;
for (int i = 0; i < input; i++) {
String test = Integer.toString(i);
if (i < 10 && (test.equals("2") || test.equals("3"))) {
System.out.println("The digit is " + i);
} else {
for (int j = 0; j < test.length(); j++) {
if (test.charAt(j) == '2') {
two++;
} else if ((test.charAt(j) == '3')) {
three++;
}
}
if (two >= 1 && three >= 1) {
System.out.println("The digit is " + i);
}
two = 0;
three = 0;
}
}
}
I am trying to make a simple program in Java that would output all the prime numbers (skipping number 2) up to the number n. It doesn't work and I am out of ideas. If someone could take a look at my code and tell me what the problem is I would greatly appreciate it.
public class PrimeNum {
public static void main(String[] args) {
int n = 50;
int notAPrime = 0;
System.out.println("All prime numbers before number " +n+ " are : ");
for(int i = n; i > 2; i--){
for(int j = 2; j < i; j++){
if(i % j == 0){
notAPrime++;
}
}
if(notAPrime == 0){
System.out.println(i);
notAPrime = 0;
}
}
}
}
Just declare notAPrime inside for(int i = n; i > 2; i--) to make it local for each i - candidate to be prime.
Now you increase notAPrime and never reset it to zero.
try this
public class primeNum {
public static void main(String[] args) {
int n = 50;
boolean prime;
System.out.println("All prime numbers before number " +n+ " are : ");
for(int i = n; i > 2; i--){
prime = true;
for(int j = 2; j < i; j++){
if(i % j == 0){
prime = false;
}
}
if(prime){
System.out.println(i);
}
}
}
}
note, that i changed your "notAPrime" variable from int into boolean and into a name that tells you what it means. if you only increment the "notAPrime" integer, you will never get any desired outcome.
By the way, this wa a hotfix and you got a corrected first form of your code. Have in mind, that 2 is a prime number aswell and your code ignores this.
Just work a little mor on it ;)
You are missing a "break" in your for loop.
public class primeNum {
public static void main(String[] args) {
int n=50;
int notAPrime=0;
System.out.println("All prime numbers before number " +n+ " are : ");
for(int i=n; i>2; i--){
for(int j=2; j<i; j++){
if(i%j==0){
notAPrime++;
break; //your program is missing this statement
}
}
if(notAPrime==0){
System.out.print(i + " ");
}
notAPrime=0; //In your program it is inside the if statement which makes it incorrect.
}
}
}
Output:
All prime numbers before number 50 are :
47 43 41 37 31 29 23 19 17 13 11 7 5 3
You can make your program more efficient by making the following changes:
public class primeNum {
public static void main(String[] args) {
int n=50;
int notAPrime=0;
System.out.println("All prime numbers before number " +n+ " are : ");
for(int i=n; i>2; i--){
if(i%2==0){
continue;
}
for(int j=3; j<i; j+=2){
if(i%j==0){
notAPrime++;
break;
}
}
if(notAPrime==0){
System.out.print(i + " ");
}
notAPrime=0;
}
}
}
I am supposed to get this series
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
NOTE:The spaces mentioned have to be present it should have the exact same output as i have mentioned
I tried this:
class pattern_19
{
static void main()
{
int i,j;
int s=1;
System.out.println(s);
for(i=1;i<=6;i++)
{
for(j=1;j<=i;j++)
{
s=s*11;
}
System.out.println(s);
s=1;
}
}
}
MY OUTPUT:
11
121
1331
14641
161051
1771561
This did not work any help will be appreciated
Your code would not compile because your main method was not defined correctly. This is one thing but not the main reason why you were getting an unexpected output.
Your s variable represent one integer on each line.
What you'll have to do from there is split your int and print each one of the digits seperately.
Here is a correction, I used an enhanced loop and a charArray to print the digits seperately but there are other ways to achieve this of course (using a loop and integer division works also or modify the way you find s).
Solution
public static void main(String[] args) {
int i, j;
int s = 1;
System.out.println(s + " ");
for (i = 1; i <= 6; i++) {
for (j = 1; j <= i; j++) {
s = s * 11;
}
for (char c : String.valueOf(s).toCharArray()) System.out.print(c + " ");
System.out.println();
s = 1;
}
}
PS : Multiplying by 11 wont work when you'll need numbers with a length of 2. I'll edit my answer right now.
Here is the algorithm solution
public static void main(String[] args) {
int rows = 6;
int[][] triangle = new int[rows][rows];
for (int i = 1; i <= rows; i++) {
for (int j = 0; j < i; j++) {
if (j == 0) triangle[i - 1][j] = 1;
else triangle[i - 1][j] = triangle[i - 2][j - 1] + triangle[i - 2][j];
System.out.print(triangle[i - 1][j] + " ");
}
System.out.println();
}
}
I finally also got an alternative to do the same here it goes
public class PascalTriangle {
public static void main() {
int rows = 6;
for (int i = 0; i < rows; i++) {
int number = 1;
System.out.format("%" + (rows - i) * 2 + "s", "");
for (int j = 0; j <= i; j++) {
System.out.format("%4d", number);
number = number * (i - j) / (j + 1);
}
System.out.println();
}
}
}
Now this one is working properly .
I am working on printing a quasi-empty square that looks like the example below (10 asterisks across and 10 down for the 2 columns):
**********
* *
* *
* *
* *
* *
* *
* *
* *
**********
My code cannot dynamically generate squares as specified by the user's input for the number of rows and columns (it is working for 10 rows and 10 columns, but as soon as I change the number to 20, the number of the asterisks does not change. The following is my code:
String STAR = "*";
String star1 = "**********";
int MAX = 10;
for (int row = 0; row <= MAX; row += 1 ) {
for (int col = 0; col <= MAX ; col += 10) {
if (row == 0 && col == 0)
System.out.println(star1);
if (row >= 1 && row <= 4)
System.out.println(STAR + " " + STAR);
if (row == 10 && col == 10)
System.out.println(star1);
}
}
Any help/advice is welcomed regarding the dynamism of the code.
String star = "*";
String space = " ";
int MAX = xxx;
for (int row = 0; row < MAX; row++) {
for (int col = 0; col < MAX; col++) {
if (row == 0 || row == MAX - 1) {
System.out.println(star);
} else if (col == 0 || col == MAX - 1) {
System.out.println(star);
} else {
System.out.println(space);
}
}
}
Look at your nested loop:
for (int col = 0; col <= MAX ; col += 10) {
So when col is 10, you're really only just iterating once... you might as well not have the nested loop at all.
Additionally, both star1 and the string literal with spaces have a fixed number of characters in them, clearly related to the number of columns.
I'm assuming this is homework, so I won't give any more hints than that to start with, but hopefully that'll get you thinking along the right lines...
You should change the 3 occurrences of 10 in your two for loops by the MAX variable, so when the user define another size, your for loop will take his input instead of the 10 value.
Also take a look at your last if statement there where it says if (row == 10 && col == 10) and think about it for a second. Once you have hit 10 rows and 10 columns, you are just going to print your final horizontal line of star1 regardless of what MAX is set too.
Like mentioned above, the nested for loop is unnecessary and can be inefficient if you plan to create larger rectangles in the future (not saying you're going to have to but try to stay away from nested for loops if you can). Instead, just print star1 before your loop begins and after it exits. The body of the loop should be simple enough. Hope this helps.
class Square
{
public static void main(String[] args)
{
String tenStars="**********";
String oneStar="*";
int count=0;
System.out.println(tenStars);
count++;
while(count<=8)
{
System.out.println(oneStar+" "+oneStar);
count++;
}
System.out.print(tenStars);
}
}
this should work
public static void hallowSquare(int side)
{
int rowPos, size = side;
while (side > 0)
{
rowPos = size;
while (rowPos > 0)
{
if (size == side || side == 1 || rowPos == 1 || rowPos == size)
System.out.print("*");
else
System.out.print(" ");
rowPos--;
}
System.out.println();
side--;
}
}
you can use something like this with one user input ... this is working
public static void drawSquare(int size)
{
for(int i=1; i<size ;i++)
System.out.print("*");
System.out.println("");
for(int i=0; i<50 ;i++)
{
System.out.print("*");
for(int j =0; j<size-3; j++)
System.out.print(" ");
System.out.println("*");
}
for(int i=1; i<size ;i++)
System.out.print("*");
}
public static void main(String[] args) {
// TODO Auto-generated method stub
drawSquare(50);
}
you should just create a class in put this inside your class and run it ... I hope this will help you ....
class Star8
{
public static void main(String[] args)
{
for(int i=1;i<=5;i++)
{
for(int j=1;j<=5;j++)
{
if(i==2||i==3||i==4 )
{
System.out.print("* *");
break;
}
else
{
System.out.print("*");
}
}
System.out.println();
}
}
}
Hope this helps, simplify your thinking mate. Think about the axis x and y and work by that logic. Make a nested loop on ur for loop that passes lines, in each case loop the number of
the size of square and print a space, after the nested loop print the "*".
> for (int b=0;b<ans*2-3;b++)
This nested loop has the max value of b because:
remember that while ur printing, each "*" is distanced from the other by a space, and remember u are only counting space between the first and last column. Meaning all space
between x=0 and x=squaresize, therefore max b should be the space between these 2 coords.
which are: squaresize * 2 /the 2 is for the added spaces/ -3/* -3 because u leave out the first coord(x=0),last coord(x=squaresize), AND 1 space added from the former loop.
import java.util.Scanner;
public class AsteriksSquare {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input= new Scanner(System.in);
int ans;
System.out.print("Enter the size of the side of the square: ");
ans=input.nextInt();
String ast="*";
if (ans>0 && ans<21){
for(int i=0;i<=ans-1;i++){
System.out.print("* ");
}
System.out.println("");
for(int i=1;i<=ans-2;i++){
System.out.print("*");
for (int b=0;b<ans*2-3;b++){
System.out.print(" ");
}
System.out.println("*");
}
for(int i=1;i<=ans;i++){
System.out.print("* ");
}
}
}
}
class square1
{
public static void main(String[] args)
{
String star = "*";
String space = " ";
int MAX = 5;
for (int row = 0; row < MAX; row++)
{
for (int col = 0; col < MAX; col++)
{
if (row == 0 || row == MAX - 1)
{
System.out.print(star);
} else if (col == 0 || col == MAX - 1)
{
System.out.print(star);
} else {
System.out.print(space);
}
}
System.out.println();
}
}
}
This code should do the trick.
package javaPackage;
public class Square {
public static void main(String [] args)
{
for (int i=0;i<=10;i++)
{
for (int j=0;j<=10;j++)
{
if(i==0||i==10){
System.out.print("x");
}
else if(j==0||j==10){
System.out.print("x");
}
else{
System.out.print(" ");
}
}
System.out.println();
}
}
}
If the interpreter sees that you're on the first and last line(i=0 and i=10), it will fill the row with x. Else, it will only print a x at the beginning and the end of the row.
you can use below two methods.
1) One with minimal line of code.
for (int i = 0; i <= 9; i++) {
if (i == 0 || i == 9) {
System.out.println("* * * *");
} else {
System.out.println("* *");
}
}
OR
2) With the help of two for loops
for (int i = 0; i <= 9; i++) {
for (int j = 0; j <= 9; j++) {
if (i == 0 || i == 9) {
System.out.print("*");
} else {
if (j == 0 || j == 9) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
}
System.out.println();
}
Thanks,
Stuti
Here's another solution, a more versatile one. It lets you create a hollow rectangle of height "h" and width "w"
private static void hallowSquare(int h, int w)
{
for(int i=1; i<=h; i++)
{
for(int j=1; j<=w; j++)
{
if (j==1|| j==w || i==1 || i==h )
System.out.print("X");
else
System.out.print(" ");
}
System.out.println();
}
}
import java.util.Scanner;
class Star
{
public static void main(String...args)
{
Scanner sc = new Scanner(System.in);
System.out.print("Enter the row : ");
int row=sc.nextInt();
System.out.print("Enter the column : ");
int column=sc.nextInt();
for(int i=1;i<=column;i++)
{
System.out.print("*");
}
for(int i=row-2;i>=1;i--)
{
System.out.println();
System.out.print("*");
for(int k=1;k<=column-2;k++)
{
if(i<1)
{
break;
}
System.out.print(" ");
}
System.out.print("*");
}
System.out.println();
for(int i=1;i<=column;i++)
{
System.out.print("*");
}
}
}
I am hopeful the code below can help, used very simple coding and have the required result.
a=eval(input('Provide the height of the box: '))
b=eval(input('Provide the width of the box: '))
d=a-2
r=b-2
if a >= 1:
print('*'*b)
if a > 1:
for i in range(d):
print('*',end='')
for i in range(r):
print(' ',end='')
print('*')
print('*'*b,end='')
The result is:
I have this program that takes user input and displays the number of times each integer is entered. I pretty much have it down pat but need another loop to omit the shown occurrence of 0. In other words any number with 0 in it cannot be read, also for some reason i am getting two outputs from the same number in my program. For example, if I enter 3,3 I will get 3 occurs 1 time and 3 occurs 2 times as output. The 2 times one being correct and the first one being incorrect.
public class Six_Three {
public static void main(String[] args) {
Scanner input = new Scanner (System.in);
System.out.print("enter integers between 1 and 100: ");
int[] num = new int[100];
int data = input.nextInt();
while ((data = input.nextInt()) != 0) {
num[data]++;
}
for (int i = 1; i < 100; ++i) {
if (num[i] > 0)
System.out.println(i + " occurs " + num[i] + " times ");
}
}
You need two separate loops: the first to gather the information, and the second to print the results:
int data = 0;
while ((data = input.nextInt()) != 0)
{
num[data]++;
}
for (int i = 0; i < 100; ++i)
{
if (num[i] != 0) { /* print num[i] */ }
}
Just loop over the num array after your while loop to print the counts.
for (int index = 0; index < num.length; index++) {
if (num[index] != 0)
System.out.println(data + " occurs " + num[data] + " time(s).");
}
You are printing an output every time an integer is read. Your program is behaving as expected.
To get what you want, you need to scan all the input before you produce any output.
Try this instead:
while (data != 0){
data = input.nextInt();
num[data]++;
}
for (int i = 1; i < 100; ++i) { // your version is 0...99, else array index out of bounds
if (num[i] > 0)
System.out.println(i + " occurs " + num[i] + " times ");
}
The way you write it the last number has to be 0 to make the scanning stop. It might be a good idea to check if there's another int available and use that as a condition for the scanning loop. That way your program can accept any integer.
while (input.hasNextInt()){
num[input.nextInt()]++;
}
it's so simple
int data = 0;
int[] num = new int[100];
int i = 0;
while (i < num.length) {
if ((data = input.nextInt()) == 0)
break;
num[i] = data;
i++;
}
for (i = 0; i < 100; ++i) {
int times = 0;
if (num[i] != 0) {
for (int j = 0; j < 100; j++) {
if (num[j] == 0) {
break;
} else if (num[i] == num[j]) {
times++;
}
}
System.out.println(num[i] + " occurs " + times + " times ");
} else {
break;
}
}