Create 63.cpp

Added solution for Unique paths II

Author: angie1015

leetcode/cpp/dynamic programming/63.cpp

@@ -0,0 +1,31 @@
+//Unique Paths II
+
+class Solution {
+public:
+    int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
+        if (obstacleGrid[0][0] == 1) {
+            return 0;
+        }
+        int n= obstacleGrid.size();
+        int m= obstacleGrid[0].size();
+        vector<vector<int> > dp(n,vector<int> (m, 0));
+        int  i, j;
+        dp[0][0]=1;
+        for(i=1; i<n; i++){
+            if(obstacleGrid[i][0]==0)
+                  dp[i][0]=dp[i-1][0];
+        }
+        for(i=1; i<m; i++){
+            if(obstacleGrid[0][i]==0)
+                  dp[0][i]=dp[0][i-1];
+        }
+        for(i=1; i<n; i++){
+            for(j=1; j<m; j++){
+                if(obstacleGrid[i][j]==0){
+                        dp[i][j]= dp[i-1][j] + dp[i][j-1];
+                }
+            }
+        }
+        return dp[n-1][m-1];
+    }
+};