[Algorithm] Leetcode_Contains Dublicate

Problem

Question
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.

Example 1:

Input: nums = [1,2,3,1]
Output: true

Example 2:

Input: nums = [1,2,3,4]
Output: false
Example 3:

Input: nums = [1,1,1,3,3,4,3,2,4,2]
Output: true

**Constraints:**

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109

Analysis & Solution

• for loop 사용하여 비교할 경우, time limit 발생할 수 있음
• array 정렬 후에 이전 값이랑 같은지 비교

Code

class Solution {
public:
    bool containsDuplicate(vector<int>& nums) {
        sort(nums.begin(),nums.end()); //sort(pointer, size)
    
        for(int i = 1; i < nums.size(); i++) {
            if(nums[i] == nums[i - 1]) {
                return true;
            }
        }

    return false;
    }
};