From 63d05a377a1d8af83017b75ff28c507c420b668c Mon Sep 17 00:00:00 2001
From: Tiger <tigerliu06@gmail.com>
Date: Mon, 5 May 2025 12:00:38 -0400
Subject: [PATCH 1/3] added my solution for problem 1

---
 Python/TwoSum.py | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 Python/TwoSum.py

diff --git a/Python/TwoSum.py b/Python/TwoSum.py
new file mode 100644
index 00000000..4a3c0a72
--- /dev/null
+++ b/Python/TwoSum.py
@@ -0,0 +1,7 @@
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        for i in range(len(nums)):
+            for j in range(i+1, len(nums)):
+                if nums[i] + nums[j] == target:
+                    ans = [i, j]
+                    return ans
\ No newline at end of file

From 277ee6c0baad1bc7a369b7d92a58d9aa86acdda5 Mon Sep 17 00:00:00 2001
From: Tiger <tigerliu06@gmail.com>
Date: Tue, 6 May 2025 11:59:51 -0400
Subject: [PATCH 2/3] added my solution to 26

---
 Python/26_Remove_Duplicates_from_Sorted_Array.py | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 Python/26_Remove_Duplicates_from_Sorted_Array.py

diff --git a/Python/26_Remove_Duplicates_from_Sorted_Array.py b/Python/26_Remove_Duplicates_from_Sorted_Array.py
new file mode 100644
index 00000000..a62f3a97
--- /dev/null
+++ b/Python/26_Remove_Duplicates_from_Sorted_Array.py
@@ -0,0 +1,8 @@
+class Solution:
+    def removeDuplicates(self, nums: List[int]) -> int:
+        i = 1
+        while i<len(nums): #traverse array
+            if nums[i] == nums[i-1]: #if the current element is same as previous, then remove
+                nums.pop(i)
+            else:
+                i += 1
\ No newline at end of file

From 342c0c02be42dabb81d6e20155d685b77e015fd5 Mon Sep 17 00:00:00 2001
From: Tiger <tigerliu06@gmail.com>
Date: Wed, 7 May 2025 16:10:50 -0400
Subject: [PATCH 3/3] added my solution for 20

---
 Python/20_Valid_parentheses.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Python/20_Valid_parentheses.py

diff --git a/Python/20_Valid_parentheses.py b/Python/20_Valid_parentheses.py
new file mode 100644
index 00000000..6114ae70
--- /dev/null
+++ b/Python/20_Valid_parentheses.py
@@ -0,0 +1,21 @@
+class Solution:
+    def isValid(self, s: str) -> bool:
+        stack = []
+        for i in range(len(s)):
+            if s[i] == "(" or s[i] == "[" or s[i] == "{": #check if an open bracket, push to stack
+                stack.append(s[i])
+            if s[i] == ")" or s[i] == "]" or s[i] == "}": #check if closing bracket, pop from stack and compare
+                if len(stack) == 0:
+                    return False
+                prev = stack.pop()
+                if prev == "(" and s[i] != ")":
+                    return False
+                if prev == "[" and s[i] != "]":
+                    return False
+                if prev == "{" and s[i] != "}":
+                    return False
+
+        if len(stack) == 0:
+            return True
+        else: 
+            return False
\ No newline at end of file