From a3463715de9993b8743b399a0b9add0e4a66e882 Mon Sep 17 00:00:00 2001
From: Vibhav Pata <137221624+Darky321@users.noreply.github.com>
Date: Tue, 30 Jun 2026 12:52:51 -0700
Subject: [PATCH] Update: 0001-two-sum.py - add improved two-pass solution

---
 python/0001-two-sum.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/python/0001-two-sum.py b/python/0001-two-sum.py
index e3eb994d3..17866537b 100644
--- a/python/0001-two-sum.py
+++ b/python/0001-two-sum.py
@@ -1,3 +1,4 @@
+# Hash Map (One Pass)
 class Solution:
     def twoSum(self, nums: List[int], target: int) -> List[int]:
         prevMap = {}  # val -> index
@@ -7,3 +8,25 @@ def twoSum(self, nums: List[int], target: int) -> List[int]:
             if diff in prevMap:
                 return [prevMap[diff], i]
             prevMap[n] = i
+
+
+# Hash Map (Two Pass)
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        indices = {}  # val -> index
+         
+        for i, n in enumerate(nums):
+            indices.setdefault(n, []).append(i)
+        
+        for i, n in enumerate(nums):
+            diff = target - n
+            
+            # Temporarily pop current num "n" from map
+            indices[n].remove(i)
+            result = indices.get(diff, [])
+            if result:
+                return [i, result[0]]
+
+            # If diff not found, add current num "n" back to map
+            indices[n].append(i)
+