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.
1. 我的答案 (动态规划,仍用一个辅助数组)(提交后发现竟然击败100%,哈哈,嘚瑟一下~)
class Solution {
public:
int min(int a,int b){
return a < b? a : b;
}
int minPathSum(vector<vector<int>>& grid) {
int row = grid.size();
int col = grid[0].size();
if(row == 1 && col == 1)
return grid[0][0];
vector<int>vec(row,0);
vec[0] = grid[0][0];
for(int k = 1; k < row; k++)
vec[k] = grid[k][0]+vec[k-1];
for(int j = 1; j < col; j++)
for(int i = 0; i < row; i++){
if(i == 0)
vec[i] += grid[i][j];
else
vec[i] = min(vec[i],vec[i-1])+grid[i][j];
}
return vec[row-1];
}
};