leetcode64 Minimum Path Sum

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.

Note: You can only move either down or right at any point in time.

class Solution {
public:
    int minPathSum(vector<vector<int>>& grid) {
        int m=grid.size();
        if(!m)
            return 0;
        int n=grid[0].size();
        
        vector<int> jlist(n,0);
        int t=0;
        for(int i=n-1;i>=0;i--)
        {
            jlist[i]=grid[m-1][i]+t;
            t=jlist[i];
        }
        
        for(int i=m-2;i>=0;i--)
        {
            for(int j=n-1;j>=0;j--)
            {
                int temp;
                if(j==n-1)
                {
                    temp=jlist[j];
                }
                else
                {
                    temp=jlist[j]>jlist[j+1]?jlist[j+1]:jlist[j];
                }
                jlist[j]=grid[i][j]+temp;
            }
        }
        return jlist[0];
        
    }
};