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Author: assassint2017

Unique Paths/Unique_Paths.py

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+# 第一种思路，使用组合计算公式
+# 36ms 96.05%
+class Solution:
+    def uniquePaths(self, m, n):
+        """
+        :type m: int
+        :type n: int
+        :rtype: int
+        """
+        def factorial(num):
+            if num is 0:
+                return 1
+            else:
+                return num * factorial(num - 1)
+        
+        def combination(m, n):
+            return factorial(n) // factorial(m) // factorial(n - m)
+        
+        return combination(m - 1, m - 1 + n - 1)