[paran22] Week 01 solutions

contains-duplicate/paran22.py

@@ -0,0 +1,4 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        unique_nums = set(nums)
+        return len(unique_nums) != len(nums)

two-sum/paran22.py

@@ -0,0 +1,10 @@
+class Solution:
+    # 시간복잡도 : O(n)
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        num_dict = {num: i for i, num in enumerate(nums)}
+
+        for i, first_num in enumerate(nums):
+            second_num = target - first_num
+            if second_num in num_dict and num_dict[second_num] != i:
+                return [i, num_dict[second_num]]
+