solved 0046_Permutations problem on leetcode

LeetCode/0046_Permutations.py

@@ -0,0 +1,18 @@
+class Solution:
+
+    def rec(self, sinput, index, ans):
+        n = len(sinput)
+        if(index == n-1):
+            ans.append(sinput.copy())
+            return
+
+        for i in range(index, n):
+            sinput[i], sinput[index] = sinput[index], sinput[i]
+            self.rec(sinput, index+1, ans)
+            sinput[i], sinput[index] = sinput[index], sinput[i]
+
+    def permute(self, nums):
+        ans = []
+        index = 0
+        self.rec(nums, index, ans)
+        return ans