cpp/Minimum Path Sum at main · Pi-Programmer/cpp · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
class Solution {
   /* private:
    int solve(int i,int j,vector<vector<int>>& grid,vector<vector<int>>dp){
        if(i==0 && j==0){
            return grid[i][j];

        }
        if(i<0|| j<0){
            return 1e8;
        }
        if(dp[i][j]!=-1){
            return dp[i][j];
        }
        int left=grid[i][j]+solve(i-1,j,grid,dp);
        int right=grid[i][j]+solve(i,j-1,grid,dp);
        dp[i][j]=min(left,right);
        return dp[i][j];

    }*/
public:
    int minPathSum(vector<vector<int>>& grid) {
        int n=grid.size();
        int m=grid[0].size();
        // vector<vector<int>>dp(r,vector<int>(c,-1));
      // return  solve(r-1,c-1,grid,dp);

         vector<vector<int>>dp(n,vector<int>(m,0));
       for(int i=0; i<n ; i++){
        for(int j=0; j<m; j++){
            if(i==0 && j==0){ dp[i][j] = grid[i][j];}

                else{

                int up = grid[i][j];
                if(i>0) up += dp[i-1][j];
                else up += 1e9;

                int left = grid[i][j];
                if(j>0) left+=dp[i][j-1];
                else left += 1e9;


                    dp[i][j]=min(up,left);

                }
            }
        }
        return dp[n-1][m-1];


    }
};