diff --git a/3 Sum.py b/3 Sum.py
new file mode 100644
index 00000000..7ce904bf
--- /dev/null
+++ b/3 Sum.py	
@@ -0,0 +1,37 @@
+#time complexity -0(n^2) and space complexity - o(1)
+class Solution:
+    def threeSum(self, nums: List[int]) -> List[List[int]]:
+        result=[]
+        nums.sort()
+        n=len(nums)
+
+        for i in range (n-2):
+            if i!=0 and nums[i]==nums[i-1]:
+                continue
+            if nums[i]>0:
+                break 
+            l= i+1
+            h=n-1
+            while l< h :
+                sum = nums[i]+nums[l]+nums[h]
+
+                if sum== 0:
+                    result.append([nums[i],nums[l],nums[h]])
+
+                    l= l+1
+                    h= h-1
+
+                    while (l<h and nums[l]==nums[l-1]):
+                        l= l+1
+                    while (l<h and nums[h]==nums[h+1]):
+                        h = h-1   
+                elif sum <0:
+                    l= l+1
+                else:
+                    h= h-1
+        return result
+                
+            
+
+
+        
\ No newline at end of file
diff --git a/Container with most water.py b/Container with most water.py
new file mode 100644
index 00000000..1bd0247c
--- /dev/null
+++ b/Container with most water.py	
@@ -0,0 +1,17 @@
+#time complexity -0(n) and space complexity - o(1)
+class Solution:
+    def maxArea(self, height: List[int]) -> int:
+        result =0
+
+        l= 0
+        h=len(height)-1
+
+        while l<h:
+            area = min(height[l], height[h])* (h-l)
+            result= max(result, area)
+
+            if height[l]<=height[h]:
+                l= l+1
+            else:
+                h= h-1
+        return result
\ No newline at end of file
diff --git a/Sort Colors.py b/Sort Colors.py
new file mode 100644
index 00000000..a8c628d6
--- /dev/null
+++ b/Sort Colors.py	
@@ -0,0 +1,21 @@
+#Time complexity - 0(n) & space complexity - o(1)
+class Solution:
+    def sortColors(self, nums: List[int]) -> None:
+        if nums==None or len(nums)==0:
+            return
+        n= len(nums)
+        low=0  # storing 0
+        high= n-1 #storing  2
+        mid = 0  # storing 1
+
+        while mid<=high:
+            if nums[mid]==0:
+                nums[mid],nums[low]= nums[low], nums[mid]
+                low=low+1
+                mid=mid+1
+            elif nums[mid]==1:
+                mid = mid+1
+            else:
+                nums[mid],nums[high]=nums[high], nums[mid]
+                high = high-1
+            
\ No newline at end of file