Question86.cpp

86 -> Minimum Path Sum

Solution :
class Solution {
public:
    // int solve(int i,int j,vector<vector<int>>&grid,vector<vector<int>>&dp){
    //     if(i==0&&j==0)return grid[0][0];
    //     if(i<0||j<0)return 1e9;
    //     if(dp[i][j]!=-1)return dp[i][j];
    //     int up=grid[i][j]+solve(i-1,j,grid,dp);
    //     int left=grid[i][j]+solve(i,j-1,grid,dp);
    //     return dp[i][j]=min(up,left);
    // }
    int minPathSum(vector<vector<int>>& grid) {
        int m=grid.size();
        int n=grid[0].size();
        vector<vector<int>>dp(m,vector<int>(n,-1));
        // return solve(m-1,n-1,grid,dp);
        for(int i=0;i<m;i++){
            for(int j=0;j<n;j++){
                if(i==0&&j==0)dp[0][0]=grid[0][0];
                else{int up=1e9,left=1e9;
                if(i-1>=0)
                    up=grid[i][j]+dp[i-1][j];
                if(j-1>=0)
                    left=grid[i][j]+dp[i][j-1];
                dp[i][j]=min(up,left);
                    }
            }
        }
        return dp[m-1][n-1];
    }
};