diff --git a/solutions/63. Unique Paths II.md b/solutions/63. Unique Paths II.md new file mode 100644 index 0000000..e293f53 --- /dev/null +++ b/solutions/63. Unique Paths II.md @@ -0,0 +1,23 @@ +# [63. Unique Paths II](https://leetcode.com/problems/unique-paths-ii/) +# 思路 +这题其实和[62. Unique Paths](https://leetcode.com/problems/unique-paths/)几乎一样的,唯一区别就是矩形网格里存在一些障碍物,我们对每个格子判断一下就行了。 +就是一个简单的动归,可参考[62题题解](https://github.com/ShusenTang/LeetCode/blob/master/solutions/62.%20Unique%20Paths.md)。 +时间空间复杂度都是O(mn) + +# C++ +``` C++ +class Solution { +public: + int uniquePathsWithObstacles(vector>& obstacleGrid) { + int m = obstacleGrid.size(), n = obstacleGrid[0].size(); + vector>dp(m + 1, vector(n + 1, 0)); + dp[1][1] = 1; + for(int i = 1; i <= m; i++) + for(int j = 1; j <= n; j++){ + if(obstacleGrid[i - 1][j - 1]) dp[i][j] = 0; // 此处为障碍物 + else dp[i][j] += (dp[i - 1][j] + dp[i][j - 1]); + } + return dp[m][n]; + } +}; +```