[2428] Hour Glass Sum

Author: Chhavi Bansal

LeetcodeProblems/Algorithms/2428.Hour_Glass_Sum.js

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+/*
+2428. Maximum Sum of an Hourglass
+
+You are given an m x n integer matrix grid.
+We define an hourglass as a part of the matrix with the following form:
+Return the maximum sum of the elements of an hourglass.
+
+Note that an hourglass cannot be rotated and must be entirely contained within the matrix.
+Input: grid = [[6,2,1,3],[4,2,1,5],[9,2,8,7],[4,1,2,9]]
+Output: 30
+
+
+*/
+
+/**
+ * @param {number[][]} grid
+ * @return {number}
+ */
+ var maxSum = function(grid) {
+  const m = grid.length;
+  const n = grid[0].length;
+  if(m<3 || n < 3) {
+      return 0;
+  }
+  let max = 0;
+  for(let i = 0; i<m-2; i++)
+      for(let j = 0; j<n-2;j++)
+      {
+          let cur = grid[i][j] + grid[i][j+1] + grid[i][j+2] + grid[i+1][j+1] + grid[i+2][j] + grid[i+2][j+1] + grid[i+2][j+2];
+          max = Math.max(cur, max);
+      }
+  return max;  
+};