two sum sol

Author: MJ Kang

contains-duplicate/mandoolala.py

@@ -20,4 +20,5 @@ def containsDuplicate(self, nums: List[int]) -> bool:
                 return True
             nums_set.add(num)
         return False
-        '''
+        '''
+        

two-sum/mandoolala.py

@@ -0,0 +1,27 @@
+from typing import List
+
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        # return indices of two numbers such that they add up to target
+        '''
+        [Complexity]
+        Time: O(n)
+        Space: O(1)
+        '''
+        nums_dict = {}
+        for idx, num in enumerate(nums):
+            remaining = target - num
+            if remaining in nums_dict:
+                return [idx, nums_dict[remaining]]
+            nums_dict[num] = idx
+        '''
+        [Complexity]
+        Time: O(n^2)
+        Space: O(1)
+
+        for i in range(0,len(nums)-1):
+            for j in range(i+1, len(nums)):
+                sum = nums[i] + nums[j]
+                if sum == target:
+                    return [i, j]
+        '''