0063 issue, python file added

Python/0063.py

@@ -0,0 +1,30 @@
+class Solution:
+    def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int:
+        #m rows, n cols
+
+        m = len(obstacleGrid)
+        n = len(obstacleGrid[0])
+
+        if m<0 or n<0 or obstacleGrid[0][0] == 1:
+            return 0
+
+        dp = [[0 for i in range(n)] for j in range(m)]
+
+        dp[0][0] = 1
+
+        for col in range(1, n):
+            dp[0][col] = dp[0][col-1] if obstacleGrid[0][col] != 1 else 0
+
+        for row in range(1, m):
+            dp[row][0] = dp[row-1][0] if obstacleGrid[row][0] != 1 else  0
+
+        for row in range(1, m):
+            for col in range(1, n):
+                dp[row][col] = dp[row-1][col] + dp[row][col-1] if obstacleGrid[row][col] != 1 else 0
+
+        return dp[m-1][n-1]
+
+
+tiume - O(mn)
+space - O(mn)
+

README.md

@@ -17,6 +17,7 @@ Or from the Sheet 1 of this [Google Sheet](https://bit.ly/2EUhwnw)
 | 0053 | [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/)   | Parse array and save the best solution at each step       | [Java](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Java/0053.java)    [Python](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Python/0053.py)        | O(n) | O(1)  | Easy       | Array Dynamic Programming |  [📺](https://www.youtube.com/watch?v=vkLpz2YF8Rc)      |
 | 0055 | [Jump Game](https://leetcode.com/problems/jump-game/)                    | Iterate from last index and check if we can reach there from current index or not       | [Python](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Python/0055.py)            | O(n) | O(1)  | Medium       | Array Greedy |    [📺](https://www.youtube.com/watch?v=ymET7SJsDQc)    |
 | 0062|  [Unique Paths (Total no of unique paths in m x n matrix)](https://leetcode.com/problems/unique-paths/)                  | As the first element in each row will always be 1, so maintaining one row is enough to reach bottom-right corner of the grid       | [Java](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Java/0062.java)  [Python](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Python/0062.py)           | O(n) | O(1)  | Medium       |Array Dynamic Programming |      |
+| 0063|  [Unique Paths II (Total no of unique paths in m x n matrix with obstacles)](https://leetcode.com/problems/unique-paths-ii/)   | Create a 2D matrix of same size of the given matrix to store the results.Traverse through the created array row wise and start filling the values in it.If an obstacle is found, set the value to 0.For the first row and column, set the value to 1 if obstacle is not found.Set the sum of the right and the upper values if obstacle is not present at that corresponding position in the given matirx. Return the last value of the created 2d matrix. As the first element in each row will always be 1, so maintaining one row is enough to reach bottom-right corner of the grid       |  [Python](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Python/0063.py)           | O(mn) | O(mn)  | Medium       |Array Dynamic Programming |     [📺](https://www.youtube.com/watch?v=QrdLXzlefSM)   |
 | 0070 | [Climbing Stairs](https://leetcode.com/problems/climbing-stairs/)   | steps[n]=steps[n-1]+steps[n-2].       | [C++](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/C++/0070.cpp)     [Python](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Python/0070.py)    | O(n) | O(1)  | Easy       | Dynamic Programming |     [📺](https://www.youtube.com/watch?v=QiD2Hbwx2z0)   |
 | 0072 | [Edit Distance](https://leetcode.com/problems/edit-distance/)                    | minDis(i,j)=min(minDis(i-1,j),minDis(i,j-1),minDis(i-1,j-1))+1;       | [Java](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Java/0072.py)            | O(m*n) | O(m*n)  | Hard       | String Dynamic programming |        
 | 0073 | [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/)   |   Use the first cell of every row and column as a flag. This flag would determine whether a row or column has been set to zero.     | [C++](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/C++/0073.cpp)    [Python](https://github.com/sankalpdayal5/LeetCode-Solutions/blob/master/Python/0073.py)          | O(m*n) | O(1)  | Medium       | Array |     [📺](https://www.youtube.com/watch?v=W1I7slnETp4)   |