easy backtrack

46-240610-pass/main.py

@@ -0,0 +1,26 @@
+class Solution:
+    def permute(self,nums: list[int]) -> list[list[int]]:
+        length = len(nums)
+        l = [i for i in range(length)]
+        permute = []
+        s = set()
+        def get_permute(l, num, length, s, cur):
+            if num == length: 
+                permute.append(cur)
+                return
+            for i in range(length):
+                if i not in s:
+                    s.add(i)
+                    cur.append(i)
+                    get_permute(l, num+1, length, s, cur.copy())
+                    cur.pop()
+                    s.remove(i)
+        get_permute(l,0,length, s, cur=[])
+        rlt = []
+        for li in permute:
+            rlt.append([nums[i] for i in li])
+        return rlt
+
+sol = Solution()
+print(sol.permute([1, 2, 3]))
+