Create contains_duplicate.py

Shorya22 · Shorya22 · commit 34f63d012f56 · 2025-08-01T22:40:28.000+05:30
diff --git a/arrays_hashing/contains_duplicate.py b/arrays_hashing/contains_duplicate.py
@@ -0,0 +1,39 @@
+# Given an integer array nums, return true if any value appears more than once in the array, otherwise return false.
+# Example:
+# Input: nums = [1, 2, 3, 3]
+# Output: true
+
+# method 1: using hashset
+def hasDuplicate(nums):
+    hashset = set()
+
+    for i in nums:
+        if i in hashset:
+            return True
+        hashset.add(i)
+    return False
+
+print(hasDuplicate([1,2,3,4])) # False
+print(hasDuplicate([1,1,1,3,3,4,3,2,4,2])) # True
+print(hasDuplicate([1,2,3,1])) # True
+
+# method 2: using hashmap
+def check_duplicate(nums):
+    seen = {}
+    for i in nums:
+        if i not in seen:
+            seen[i] = 1
+        else:
+            seen[i] += 1
+
+    for j in seen:
+        if seen[j] > 1:
+            return True
+    return False 
+
+print(check_duplicate([1, 2, 3, 3])) 
+print(check_duplicate([1, 2, 3, 4])) 
+print(check_duplicate([1, 1, 1, 3, 3, 4, 3, 2, 4, 2])) 
+print(check_duplicate([1, 2, 3, 1])) 
+
+
