add solution of 63

63. Unique Paths II
- https://leetcode.com/problems/unique-paths-ii/
- https://leetcode.com/explore/featured/card/april-leetcoding-challenge-2021/596/week-4-april-22nd-april-28th/3723/

Author: rushirg

solutions/unique-paths-ii.py

@@ -0,0 +1,45 @@
+"""
+63. Unique Paths II
+- https://leetcode.com/problems/unique-paths-ii/
+- https://leetcode.com/explore/featured/card/april-leetcoding-challenge-2021/596/week-4-april-22nd-april-28th/3723/
+"""
+
+# Method 1
+# DP
+
+class Solution(object):
+    def uniquePathsWithObstacles(self, obstacleGrid):
+        """
+        :type obstacleGrid: List[List[int]]
+        :rtype: int
+        """
+        row = len(obstacleGrid)
+        col = len(obstacleGrid[0])
+
+        if obstacleGrid[0][0] == 1:
+            return 0
+
+        obstacleGrid[0][0] = 1
+
+        for i in range(1, col):
+            if obstacleGrid[0][i] == 1:
+                obstacleGrid[0][i] = 0
+            else:
+                obstacleGrid[0][i] = obstacleGrid[0][i - 1]
+
+        for j in range(1, row):
+            if obstacleGrid[j][0] == 1:
+                obstacleGrid[j][0] = 0
+            else:
+                obstacleGrid[j][0] = obstacleGrid[j - 1][0]
+
+
+        for i in range(1, row):
+            for j in range(1, col):
+                if obstacleGrid[i][j] == 1:
+                    obstacleGrid[i][j] = 0
+                else:
+                    obstacleGrid[i][j] = obstacleGrid[i - 1][j] + obstacleGrid[i][j - 1]
+
+        return obstacleGrid[row - 1][col - 1]
+