2428.Maximum_Sum_of_an_Hourglass.cpp

/*
    written by Pankaj Kumar.
    country:-INDIA
*/
typedef long long ll ;


/* ascii value
A=65,Z=90,a=97,z=122
*/

/*  --------------------MAIN PROGRAM----------------------------*/
// to run ctrl+b
const ll INF=1e18;
const ll mod1=1e9+7;
const ll mod2=998244353;
// Techniques :
// divide into cases, brute force, pattern finding
// sort, greedy, binary search, two pointer
// transform into graph

// Experience :
// Cp is nothing but only observation and mathematics.


//Add main code here

class Solution
{
public:
    int maxSum(vector<vector<int>> &grid)
    {
        int n = grid.size();
        int m = grid[0].size();
        int maxo=0;
        for(int i=1;i+1<n;i++){
            for(int j=1;j+1<m;j++){
                int sum=grid[i][j]+grid[i-1][j]+grid[i+1][j]+grid[i-1][j-1]+grid[i-1][j+1]+grid[i+1][j-1]+grid[i+1][j+1];
                maxo=max(maxo,sum);
            }
        }
        return maxo;
    }
};

/* -----------------END OF PROGRAM --------------------*/
/*
* stuff you should look before submission
* constraint and time limit
* int overflow
* special test case (n=0||n=1||n=2)
* don't get stuck on one approach if you get wrong answer
*/