Largest Submatrix

/* QUESTION
  Given a matrix, find largest submatrix where the sum of its elements is zero, and print its size
 */

// First take input...

/* Example in Java using Scanner class, you can use C if you are comfortable with it*/

Scanner sc=new Scanner(System.in); //make sure you have imported Scanner class using `import java.util.Scanner;`

int m = sc.nextInt();
int n = sc.nextInt();

int matrix=new int[m][n];

for(int i=0; i<m; i++) {
  for(int j=0; j<n; j++) matrix[i][j]=sc.nextInt();
  }
  
//now input is done, use brute force to find largest sub-matrix

int size=0; //to store current size
int max=0; //to store max

for(int i=0; i<m; i++) {
  for(int j=0; j<n; j++) {
    for(int k=m-1; k>=i; k--) {
      for(int l=n-1; l>=n; l--) {
        if(matrixSum(matrix, i, j, k, l)) {
           size=(k-i+1)*(l-j+1);
           if(size>=sum) sum=size;
         }
      }
    }
  }
}
System.out.println(max);


/*******************************************************************************/

public boolean matrixSum(int[][] matrix, int i, int j, int k, int l) {

  int sum=0;
  
  for(int a=i; a<=k; a++) {
    for(int b=j; b<=l; b++) sum+=matrix[a][b];
    }
    
  return sum==0; //will return true or false
 
}