I want to print "Two" in the place of 2 and "Four" in the place of 4 in Java within a FOR Loop while printing the numbers from 1 to 50.
For example:
1
Two
3
Four
5
.
.
.
1Four
15
.
.
.
Two1
TwoTwo
Two3
TwoFour
.
.
.
50
Java 8 solution:
public class Play {
public static void main(String[] args) {
rangeClosed(1, 50).forEach(Play::twoOrFour);
}
public static void twoOrFour(long n) {
String result = n + "";
if (n % 10 == 2) {
n /= 10;
result = (n == 0 ? "" : n) + "two"; // the ternary exp: an ugly patch to get rid of the "0" in the first two cases
} else if (n % 10 == 4) {
n /= 10;
result = (n == 0 ? "" : n) + "four";
}
System.out.print(result + " ");
}
}
OUTPUT
1 two 3 four 5 6 7 8 9 10 11 1two 13 1four 15 16 17 18 19 20 21 2two 23 2four 25 26 27 28 29 30 31 3two 33 3four 35 36 37 38 39 40 41 4two 43 4four 45 46 47 48 49 50
UPDATE
In case you want to replace any occurrence of "2" with "two" and "4" with "four" the referenced method can be even simpler:
public static void twoOrFour(long n) {
String result = n + "";
result = result.replaceAll("2", "two").replaceAll("4", "four");
System.out.print(result + " ");
}
which will output:
1 two 3 four 5 6 7 8 9 10 11 1two 13 1four 15 16 17 18 19 two0 two1 twotwo two3 twofour two5 two6 two7 two8 two9 30 31 3two 33 3four 35 36 37 38 39 four0 four1 fourtwo four3 fourfour four5 four6 four7 four8 four9 50
Or if to be even funkier - it can be done in a one-liner:
rangeClosed(1, 50).forEach((x)-> System.out.print((x + " ").replaceAll("2", "two").replaceAll("4", "four")));
Related
I'm a newbie, but I'm willing to learn how to code.
I tried using this code:
int n = 50;
int counter = 0;
System.out.print("Even Numbers from 1 to "+n+" are: ");
for (int i = 1; i <= n; i++) {
counter++;
if (counter == 2) {
System.out.println(i + " ");
counter = 0;
%10== 0
to find all even numbers between 1 to 50 and make a new line at multiples of 10 just follow these steps -
Make one loop which will go 1 to 50
Check if the number is even by checking the remainder after diving it with 2, if YES print that number.
Check if the number is a multiple of 10 by checking the remainder after dividing it by 10, if YES make a new line
The code will look something like this -
int i = 1;
while(i<=50){
if(i%2 == 0) System.out.print(i + " ");
if(i%10 == 0) System.out.println();
i++;
}
Output -
2 4 6 8 10
12 14 16 18 20
22 24 26 28 30
32 34 36 38 40
42 44 46 48 50
It's up to you which looping method you want to use for me While loop looks cleaner.
I hope this solves all your queries.
PFB Snippet:
public class Main
{
public static void main(String[] args) {
for(int i=1;i<=50;i++){
if (i%2 == 0) //Check whether number is even
{
System.out.print(i+" ");
if (i%10 == 0) // Check if it is multiple of 10
{
System.out.print("\n");
}
}
}
}
}
Output:
2 4 6 8 10
12 14 16 18 20
22 24 26 28 30
32 34 36 38 40
42 44 46 48 50
"\n" is a Escape Sequence which means new line
I want to ask a question or a probable favor on how am I going to make my program coding "do-while loop" in creating a Triangular Multiplication. Is there a probable way on to create such thing without using any other statement?
public class Main {
static void ssbr(int n) {
int i = 1;
do{
System.out.printf("%4d", n * i);
i = i + 1;
} while(i <= 7);
System.out.println("");
}
public static void main(String[] args) {
int i = 1;
do{
ssbr(i);
i = i + 1;
} while (i <= 7);
}
}
Output it gave:
1 2 3 4 5 6 7
2 4 6 8 10 11 12
3 6 9 12 15 18 21
4 8 12 16 20 24 30
5 10 15 20 25 30 35
6 12 18 24 30 36 42
7 14 21 28 35 42 49
Output I wanted:
1
2 4
3 6 9
4 8 12 16
5 10 15 20 25
6 12 18 24 30 36
7 14 21 28 35 42 49
You can do it with the following algorithm:
You have to do it 7 times and therefore you can use a loop that should run 7 times.
Each row starts with the row number, and run for row number * row number times with a step-value equal to the row number.
Given below is the implementation of this algorithm using for loop and I leave it to you to implement it using the do-while loop (as it seems to be your homework 😀)
public class Main {
public static void main(String[] args) {
int n = 7;
for (int row = 1; row <= n; row++) {
for (int col = row; col <= row * row; col += row) {
System.out.printf("%-4d", col);
}
System.out.println();
}
}
}
Output:
1
2 4
3 6 9
4 8 12 16
5 10 15 20 25
6 12 18 24 30 36
7 14 21 28 35 42 49
The code below is the answer I wrote for a question that asks to rotate an n x n 2D matrix by 90 degrees (clockwise), without creating a new 2D array. So for example,
Given input matrix =
[
[1,2,3],
[4,5,6],
[7,8,9]
],
rotate the input matrix:
[
[7,4,1],
[8,5,2],
[9,6,3]
]
I tried to do it row by row, but the problem I have to deal with is what to do if the pair of index if already altered. So if I try to assign index pair [1, 2] to [0, 1], but then [0,1] is already changed before. The solution I came up with is to use a HashMap, put the index pair in an array as key, and the original number as value.
Here is my code
public void rotate(int[][] matrix) {
int n = matrix.length;
HashMap<int[], Integer> map = new HashMap<>();
for(int i = 0; i < n; i++){
for (int j = 0; j < n; j++){
if(map.containsKey(new int[]{n-j,i})){
matrix[i][j] = map.get(new int[]{n-j, i});
}
else{
int temp = matrix[i][j];
matrix[i][j] = matrix[n-j][i];
map.put(new int[]{n-j,i}, temp);
}
}
}
}
However, the result shows that
if(map.containsKey(new int[]{n-j,i})){
matrix[i][j] = map.get(new int[]{n-j, i});
}
this line of code isn't searching for the array I put in before. I know that I am creating a new array every time, but how does it make containsKey not know if the array contains same numbers(the same array)? Can anyone help me understand why using an array here to mark the pair of index isn't working in a HashMap?
You don't need a Map to rotate a matrix. You only need one temp variable.
To rotate a 3x3:
1 2 3
4 5 6
7 8 9
temp = 1, copy corner values around, then save value to next corner:
1 2 3 7 2 3 7 2 3 7 2 3 7 2 1
4 5 6 → 4 5 6 → 4 5 6 → 4 5 6 → 4 5 6
7 8 9 7 8 9 9 8 9 9 8 3 9 8 3
repeat for border values, temp = 2:
7 2 1 7 4 1 7 4 1 7 4 1 7 4 1
4 5 6 → 4 5 6 → 8 5 6 → 8 5 6 → 8 5 2
9 8 3 9 8 3 9 8 3 9 6 3 9 6 3
And you're done, in-place rotation with only 1 value in temp storage, i.e. O(1) memory footprint.
Now I'll let you actually code that, for any size matrix.
UPDATE
For the fun of it, I decided to try writing it, so here it is, with test code. I'm not going to explain the logic though, that's for you to figure out yourself.
public static void main(String... args) {
for (int size : new int[] {2,3,4,5,10}) {
int[][] matrix = createMatrix(size);
printMatrix(matrix);
System.out.println();
rotateMatrix(matrix);
printMatrix(matrix);
printSeparatorLine(matrix);
}
}
private static int[][] createMatrix(int size) {
int[][] matrix = new int[size][size];
for (int y = 0, i = 0; y < size; y++)
for (int x = 0; x < size; x++)
matrix[y][x] = ++i;
return matrix;
}
private static void rotateMatrix(int[][] matrix) {
for (int y1 = 0; y1 < matrix.length / 2; y1++) {
for (int y2 = matrix.length - y1 - 1, x1 = y1; x1 < y2; x1++) {
int x2 = matrix.length - x1 - 1, temp = matrix[y1][x1];
matrix[y1][x1] = matrix[x2][y1];
matrix[x2][y1] = matrix[y2][x2];
matrix[y2][x2] = matrix[x1][y2];
matrix[x1][y2] = temp;
}
}
}
private static void printMatrix(int[][] matrix) {
int w = maxValueWidth(matrix);
for (int[] row : matrix) {
for (int i = 0; i < row.length; i++)
System.out.printf("%" + (w + (i == 0 ? 0 : 1)) + "d", row[i]);
System.out.println();
}
}
private static void printSeparatorLine(int[][] matrix) {
char[] buf = new char[(maxValueWidth(matrix) + 1) * matrix.length - 1];
Arrays.fill(buf, '-');
System.out.println(new String(buf));
}
private static int maxValueWidth(int[][] matrix) {
return Arrays.stream(matrix).flatMapToInt(Arrays::stream).map(i -> String.valueOf(i).length()).max().getAsInt();
}
Output
1 2
3 4
3 1
4 2
---
1 2 3
4 5 6
7 8 9
7 4 1
8 5 2
9 6 3
-----
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
13 9 5 1
14 10 6 2
15 11 7 3
16 12 8 4
-----------
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
21 16 11 6 1
22 17 12 7 2
23 18 13 8 3
24 19 14 9 4
25 20 15 10 5
--------------
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
91 81 71 61 51 41 31 21 11 1
92 82 72 62 52 42 32 22 12 2
93 83 73 63 53 43 33 23 13 3
94 84 74 64 54 44 34 24 14 4
95 85 75 65 55 45 35 25 15 5
96 86 76 66 56 46 36 26 16 6
97 87 77 67 57 47 37 27 17 7
98 88 78 68 58 48 38 28 18 8
99 89 79 69 59 49 39 29 19 9
100 90 80 70 60 50 40 30 20 10
---------------------------------------
You said "this line of code isn't searching for the array I put in before". But you also acknowledge that you were creating a new object each time. That won't work:
Since arrays extend Object, but don't override hashCode() or equals(), you get the default implementations defined by Object. These require that the array is actually the exact same one as is being compared to - so it can't just be 'equivalent'. That is, another array of the same type, with the same elements in the same order, won't work.
Source: https://coderanch.com/t/399422/java/array-HashMap-Key
Instead, you should use a Pair object to store your coordinates. You can write your own implementation or use a pre-existing one, such as javafx.util.Pair
Hello fellow StackOverflowers, today I pose a strange question.
As all of you know, there are different ways in which to count (in terms of bases)
For base 2 (a.k.a binary), one would count as follows
0000 = (2^3 x 0) + (2^2 x 0) + (2^1 x 0) + (2^0 x 0) = 0
0001 = (2^3 x 0) + (2^2 x 0) + (2^1 x 0) + (2^0 x 1) = 1
0010 = (2^3 x 0) + (2^2 x 0) + (2^1 x 1) + (2^0 x 0) = 2
0011 = (2^3 x 0) + (2^2 x 0) + (2^1 x 1) + (2^0 x 1) = 3
...and so on...
When we reach bases higher than 10, such as 16 (a.k.a hexadecimal) we use letters to represent values:
For example:
200 base 16 = C8 ---> http://www.binaryhexconverter.com/decimal-to-hex-converter (if you dont believe me ;))
However, how will we count in bases higher than letters allow? (base 37+)
I wrote a simple java program to illustrate my point:
public class Testing {
public static void main(String[] args) {
for (int base = 1;base<=50;base++){
System.out.println("===========================Base " + base + "===============================");
for (int value=1; value<=50; value++){
System.out.println(value + " base " + base + " is equal to: " + Integer.toString(value, base));
}
}
}
}
Here are some snippets of the output of my program:
40 base 36 is equal to: 14
41 base 36 is equal to: 15
42 base 36 is equal to: 16
43 base 36 is equal to: 17
44 base 36 is equal to: 18
45 base 36 is equal to: 19
46 base 36 is equal to: 1a
47 base 36 is equal to: 1b
48 base 36 is equal to: 1c
49 base 36 is equal to: 1d
50 base 36 is equal to: 1e
28 base 37 is equal to: 28
29 base 37 is equal to: 29
30 base 37 is equal to: 30
31 base 37 is equal to: 31
32 base 37 is equal to: 32
33 base 37 is equal to: 33
34 base 37 is equal to: 34
35 base 37 is equal to: 35
36 base 37 is equal to: 36
37 base 37 is equal to: 37
38 base 37 is equal to: 38
39 base 37 is equal to: 39
40 base 37 is equal to: 40
41 base 37 is equal to: 41
42 base 37 is equal to: 42
43 base 37 is equal to: 43
44 base 37 is equal to: 44
45 base 37 is equal to: 45
46 base 37 is equal to: 46
47 base 37 is equal to: 47
48 base 37 is equal to: 48
49 base 37 is equal to: 49
50 base 37 is equal to: 50
As you can see, base 37+ doesn't work.
Is there anyway to fix this? Thank you!
Character.MAX_RADIX is equal to 36 (10 digits and 26 letters).
If you want to use higher values for radix, you will have to write your own method. This should not be too hard. I suggest modifying the source code for Integer.toString(int, int). The code for this method uses this array:
final static char[] digits = {
'0' , '1' , '2' , '3' , '4' , '5' ,
'6' , '7' , '8' , '9' , 'a' , 'b' ,
'c' , 'd' , 'e' , 'f' , 'g' , 'h' ,
'i' , 'j' , 'k' , 'l' , 'm' , 'n' ,
'o' , 'p' , 'q' , 'r' , 's' , 't' ,
'u' , 'v' , 'w' , 'x' , 'y' , 'z'
};
Try this.
public static String DIGITS = "0123456789abcdefghijklmnopqrstuvwxyz#!#$%&;:";
public static String toString(int i, int base) {
StringBuilder sb = new StringBuilder();
for (; i > 0; i /= base)
sb.append(DIGITS.charAt(i % base));
if (sb.length() == 0)
sb.append(0);
return sb.reverse().toString();
}
I'm new to Java. I am trying to create a multiplication table with 12 on each side of the table, so 12 going to the right and 12 going down. On each line, we will see the two values multiple. So my plan is to use 12 very similar for statements to print each of the twelve lines. One value will increment within a loop. The issue is, the first line isn't increment my y value. So it just prints out spaced out 1s.
If you have any suggestions on my latter part of the assignment, it'd be helpful. Once I get the first line to print 12 digits, I can make 11 other for statements. But I feel like there may be a simpler way to get the rest of the statements.
public class Sixthree
{
public static void main (String[] args)
{
int x = 1;
int y = 1;
System.out.print(" ");
for ( int c= x*y; y<= 12; y++)
{
System.out.print(c + " ");
}
}
}
I want the out put to look like this to start off with.:
1 2 3 4 5 6 7 8 9 10 11 12
But the current output looks like this:
1 1 1 1 1 1 1 1 1 1 1 1 1
But I want it to eventually like this: http://math.about.com/blgrid.htm
But without the blue lines.
You are getting all 1s because the loop initialization statement int c= x*y will be executed only once for a for loop. That is it is executed the first time when x=1 and y=1 and since, it is given as the loop initialisation statement and not in the loop body, it is never reevaluated. The for loop works as :
The loop initialisation statement is executed only once at the beginning of the loop. After each iteration the loop update expression is executed and the loop condition is reevaluated. for(loop_initialisation;loop_condition;loop_update) { ... }
So you should update c inside the loop, something like :
for ( int c= x*y; y<= 12; y++)
{
c = x*y;
System.out.print(c + " ");
}
for (int i = 1; i <= 12; i++) {
for (int j = 1; j <= 12; j++){
System.out.printf ("%3d ", j * i);
}
System.out.print ("\n");
}
The above code will give you output similar to what is shown below:
1 2 3 4 5 6 7 8 9 10 11 12
2 4 6 8 10 12 14 16 18 20 22 24
3 6 9 12 15 18 21 24 27 30 33 36
4 8 12 16 20 24 28 32 36 40 44 48
5 10 15 20 25 30 35 40 45 50 55 60
6 12 18 24 30 36 42 48 54 60 66 72
7 14 21 28 35 42 49 56 63 70 77 84
8 16 24 32 40 48 56 64 72 80 88 96
9 18 27 36 45 54 63 72 81 90 99 108
10 20 30 40 50 60 70 80 90 100 110 120
11 22 33 44 55 66 77 88 99 110 121 132
12 24 36 48 60 72 84 96 108 120 132 144
You should be using two nested for loops, one to iterate over the values of x, another to iterate over the values of y with each inner loop printing the value of x * y and each outer loop printing a new line character for formatting.
// Pseudo-code //
for(each x) {
for(each y) {
print(product);
}
print(newline);
}
Why it just prints out spaced out 1s ?
It is because you just assign c only once in for-loop. for ( int c= x*y; y<= 12; y++)
When value y is incvreasing, value c is not changing. The values is 1*1=1 (x=1, y=1).
As a result, you see it just prints out spaced out 1s.
You can use nested for loop to implement it.
public class Sixteen {
public static void main(String[] args) {
int x = 12;
int y = 12;
for (int i = 1; i <= x; i++) {
for (int j = 1; j <= y; j++) {
System.out.printf("%d ", i * j);
}
System.out.println();
}
}
}
for (int x = 1; x <= 12; x++)
{
for (int y = 1; y <= 12; y++)
{
int multiply = x * y;
System.out.print(multiply + "\t");
}
System.out.println();
}