Leetcode Unique Paths II

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.

[
  [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.

简单的动态规划问题

class Solution {
public:
    int dp[][];
    int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {
        memset(dp,,sizeof(dp));
        dp[][]=obstacleGrid[][] ==  ? :;
        int n = obstacleGrid.size(), m = obstacleGrid[].size();
        for(int i = ; i < n; ++ i )
            dp[i][] = obstacleGrid[i][] ==  ?  : dp[i-][];
        for(int i = ; i < m; ++ i )
            dp[][i] = obstacleGrid[][i] ==  ?  : dp[][i-];
        for(int i = ; i < n ; ++ i){
            for(int j = ; j <  m ; ++ j){
                dp[i][j] = obstacleGrid[i][j] ==  ?  : dp[i-][j] + dp[i][j-];
            }
        }
        return dp[n-][m-];
    }
};