[Leetcode][자바스크립트][Easy] 217. Contains Duplicate

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/**
 * 217_ContainsDuplicate.js
 * Easy
 * https://leetcode.com/problems/contains-duplicate/
 * @param {number[]} nums
 * @return {boolean}
 */
var containsDuplicate = function(nums) {
    const numHash = {};
    for (let i = 0; i < nums.length; i++) {
        if (!numHash[nums[i]]) {
            numHash[nums[i]] = 1;
        } else {
            return true;
        }
    }
    return false;
};

module.exports.containsDuplicate = containsDuplicate;

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간단한 해시로 확인 

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/**
 * 217_ContainsDuplicate.test.js
 */

const { containsDuplicate } = require("./217_ContainsDuplicate");

test('[1,2,3,1]', () => {
    expect(containsDuplicate([1,2,3,1])).toBe(true);
});

test('[1,2,3,4]', () => {
    expect(containsDuplicate([1,2,3,4])).toBe(false);
});

test('[1,1,1,3,3,4,3,2,4,2]', () => {
    expect(containsDuplicate([1,1,1,3,3,4,3,2,4,2])).toBe(true);
});

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