JSFiddle - React, Tailwind, and code Playground

by Shridhar Baddur

JavaScript

// Javascript program to find maximum
// sum of hour glass in matrix

let R = 5;
let C = 5;

// Returns maximum sum of hour glass in an array arr[][]
function findMaxHourGlassSum(arr) {
  if(R < 3 || C < 3) {
    return -1;
  }

  let maxSum = Number.MIN_VALUE;

  for(let i = 0; i < R - 2; i ++) {
    for(let j =0; j < C - 2; j++) {
      let sum = (
                  arr[i][j] + arr[i][j + 1] + arr[i][j + 2] +
                  arr[i + 1][j + 1] +
                  arr[i + 2][j] + arr[i + 2][j + 1] + arr[i + 2][j + 2]
                )
      maxSum = Math.max(maxSum, sum);
    }
  }
  return maxSum;

}

let mat = [[1, 2, 3, 0, 0],
            [0, 0, 0, 0, 0],
            [2, 1, 4, 0, 0],
            [0, 0, 0, 0, 0],
            [1, 1, 0, 1, 0]];
let res = findMaxHourGlassSum(mat);
if (res == -1)
  console.log("Not possible");
else
  console.log("Maximum sum of hour glass = " + res);