Leetcode 2428 Maximum Sum of an Hourglass Solution in Java | Hindi Coding Community

 

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.

 

Example 1:

Input: grid = [[6,2,1,3],[4,2,1,5],[9,2,8,7],[4,1,2,9]]
Output: 30
Explanation: The cells shown above represent the hourglass with the maximum sum: 6 + 2 + 1 + 2 + 9 + 2 + 8 = 30.

Example 2:

Input: grid = [[1,2,3],[4,5,6],[7,8,9]]
Output: 35
Explanation: There is only one hourglass in the matrix, with the sum: 1 + 2 + 3 + 5 + 7 + 8 + 9 = 35.

 

Constraints:

• m == grid.length
• n == grid[i].length
• 3 <= m, n <= 150
• 0 <= grid[i][j] <= 106 

Java Code :

class Solution {

public int maxSum(int[][] grid) {

int ans=0;

for(int i=0;i<grid.length-2;i++){

//Running the for loop for the row-2 times

for(int j=0;j<grid[0].length-2;j++){

//Running the inner for loop for the col-2 times

int sum=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];

ans=Math.max(ans,sum);

}

}

return ans;

}

}