Create number-of-paths-with-max-score.py

Author: kamyu104

Python/number-of-paths-with-max-score.py

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+# Time:  O(n^2)
+# Space: O(n)
+
+class Solution(object):
+    def pathsWithMaxScore(self, board):
+        """
+        :type board: List[str]
+        :rtype: List[int]
+        """
+        MOD = 10**9+7
+        directions = [[1, 0], [0, 1], [1, 1]]
+        dp = [[[0, 0] for r in xrange(len(board[0])+1)]
+              for r in xrange(2)]
+        dp[(len(board)-1)%2][len(board[0])-1] = [0, 1]
+        for r in reversed(xrange(len(board))):
+            for c in reversed(xrange(len(board[0]))):
+                if board[r][c] in "XS":
+                    continue
+                dp[r%2][c] = [0, 0]
+                for dr, dc in directions:
+                    if dp[r%2][c][0] < dp[(r+dr)%2][c+dc][0]:
+                        dp[r%2][c] = dp[(r+dr)%2][c+dc][:]
+                    elif dp[r%2][c][0] == dp[(r+dr)%2][c+dc][0]:
+                        dp[r%2][c][1] = (dp[r%2][c][1]+dp[(r+dr)%2][c+dc][1]) % MOD
+                if dp[r%2][c][1] and board[r][c] != 'E':
+                    dp[r%2][c][0] += int(board[r][c])
+        return dp[0][0]