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Contains Duplicate

easy

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

Test Cases

Copy an input into the main harness and Run to verify
Input
nums = [1,2,3,1]
Expected Output
true
Input
nums = [1,2,3,4]
Expected Output
false
Input
nums = [1,1,1,3,3,4,3,2,4,2]
Expected Output
true

Constraints

  • 1 <= nums.length <= 10^5
  • -10^9 <= nums[i] <= 10^9

Hints

Hint 1 — click to reveal

A hash set gives O(1) membership checks.

Hint 2 — click to reveal

If adding a number fails because it already exists, you are done.

Java Compiler

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