Java_Basi/diagonalsum.java at main · nikhilritgithub/Java_Basi · GitHub

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public class diagonalsum {
 public static int diagonalsum(int arr[][]){
    int sum = 0;
    //   BRUTE FORCE....
    // for(int i=0; i<arr.length;i++){
    //     for(int j=0; j<arr[0].length; j++){
    //         if(i == j){
    //             sum += arr[i][j];
    //         }
    //         else if(i+j == arr.length-1){
    //             sum += arr[i][j];
    //         }
    //     }
    // }
    for(int i=0; i<arr.length; i++){
        sum += arr[i][i];
      if( i!= arr.length-1-i){
        sum += arr[i][arr.length-i-1];
      }
    }
    return sum;
 }
  public static void main(String args[]){
    int arr[][]={{1,2,3,4},
                 {5,6,7,8},
                 {9,10,11,12},
                 {13,14,15,16}};
    int arr2[][]={{1,2,3},
                  {4,5,6},
                  {7,8,9}};

                 System.out.println("diagonal sum is: " + diagonalsum(arr));
                 System.out.println("diagonal sum is: " + diagonalsum(arr2));
  }
}