LeetCode题解之Unique Paths II

1、题目描述

2、问题描述

使用动态规划算法，加上条件检测即可

3、代码

 1 int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
 2         int m = obstacleGrid.size() ;
 3         int n = obstacleGrid[0].size() ;
 4         
 5         vector<vector<int>> sum(m , vector<int>(n, 0));
 6         bool isOb = false;
 7         for( int i = 0; i < m; i++){
 8             if( obstacleGrid[i][0] == 1) isOb = true;
 9             if( isOb ){
10                 sum[i][0] = 0;
11             }
12             else{
13                 sum[i][0] = 1;
14             }
15         }
16         
17         isOb = false;
18         for(int j = 0; j < n; j++){
19             if( obstacleGrid[0][j] == 1) isOb = true;
20             if( isOb ){
21                 sum[0][j] = 0;
22             }
23             else{
24                 sum[0][j] = 1;
25             }
26         }
27         
28         for(int i = 1; i < m; i++){
29             for( int j = 1; j < n; j++){
30                 if( obstacleGrid[i][j] == 1)
31                     sum[i][j] == 0;
32                 else
33                     sum[i][j]  = sum[i-1][j] + sum[i][j-1];
34             }
35         }
36         
37         return sum[m-1][n-1];
38     }

 

posted @ 2018-09-03 09:36  山里的小勇子  阅读(125)  评论(0)  编辑  收藏  举报