Unique Paths II
Desicription
Follow up for “Unique Paths”:
Now consider if some obstacles are added to the grids. How many unique paths would there be?
An obstacle and empty space is marked as 1
and 0
respectively in the grid.
For example, There is one obstacle in the middle of a 3x3 grid as illustrated below.
代码语言:javascript复制[
[0,0,0],
[0,1,0],
[0,0,0]
]
The total number of unique paths is 2
.
Note: m and n will be at most 100.
Solution
代码语言:javascript复制class Solution {
public:
int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
int n = obstacleGrid.size();
int m = obstacleGrid[0].size();
vector<vector<int>> dp(n 1, vector<int>(m 1, 0));
dp[0][1] = 1;
for(int i = 1; i <= n; i ){
for(int j = 1; j <= m; j ){
if(!obstacleGrid[i-1][j-1]){
dp[i][j] = dp[i-1][j] dp[i][j-1];
}
}
}
return dp[n][m];
}
};