Arrays-Wave print column wise

#1

When i run the code, the custom input works fine, but upon submission it shows runtime error.
What went wrong?

Code:

import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner scn = new Scanner(System.in);
int m = scn.nextInt();
int n = scn.nextInt();
int[][] arr = new int[m][n];
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
arr[i][j]=scn.nextInt();
}
System.out.println();
}

	for(int j = 0;j<n;j++){
		if(j%2==0){
			for(int i =0;i<m;i++){
				System.out.print(arr[i][j]+", ");
			}
		}else{
			for(int i=n-1;i>=0;i--){
				System.out.print(arr[i][j]+", ");
			}
		}
	}
	System.out.print("END");
}

}

#2

@Raunak-Agrawal-1537545869717573,
https://ide.codingblocks.com/s/279555 corrected code.

Error:
You have written: for(int i=n-1;i>=0;i--){

instead of: for (int i = m - 1; i >= 0; i--) {

Hence the runtime error.

#3

Thanks got it.
But it was still giving correct output while entering the custom input mentioned in the question.

#4

@Raunak-Agrawal-1537545869717573,
That’s because the test input is a 4x4 matrix. Hence m and n are equal. Your code was giving a Run time error in case m!=n

#5

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