题目:
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.
Example:
Input: [ [1,3,1], [1,5,1], [4,2,1] ] Output: 7 Explanation: Because the path 1→3→1→1→1 minimizes the sum.
代码:
class Solution { public: int minPathSum(vector<vector<int>>& grid) { vector<int> dp(grid[0].size(), 0); for(int i = 0; i < grid.size(); i++){ for(int j = 0; j < grid[0].size(); j++){ if(i == 0 && j == 0) dp[0] = grid[0][0]; else if(i != 0 && j == 0) dp[j] = dp[j] + grid[i][j]; else if(i == 0 && j != 0) dp[j] = dp[j-1] + grid[0][j]; else{ dp[j] = min(dp[j], dp[j-1]) + grid[i][j]; } } } return dp[grid[0].size()-1]; } };