leetcode-minimum path sum

属于中规中矩的dp。和unique paths类似。一次ac。

但是可以通过滚动数组来节省存储空间。

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

class Solution {
public:
    int minPathSum(vector<vector<int> > &grid) {
        vector<vector<int>> dp(grid);
        int sum = 0;
        int row = grid.size();
        int col = grid[0].size();
        for (int i = 0; i < grid.size(); i++)
        {
            sum += grid[i][0];
            dp[i][0] = sum;
        }
        sum = dp[0][0];
        for (int i = 1; i < grid[0].size(); i++)
        {
            sum += grid[0][i];
            dp[0][i] = sum;
        }
        for (int i = 1; i < grid.size(); i++)
        {
            for (int j = 1; j < grid[0].size(); j++)
            {
                dp[i][j] = min(dp[i-1][j],dp[i][j-1])+grid[i][j];
            }
        }
        return dp[row-1][col-1];
    }
};

int main()
{
    Solution s;
    vector<vector<int>> vv = { { 1, 2, 3 }, { 4, 5, 6 } };
    cout<<s.minPathSum(vv)<<endl;
    return 0;
}