Leetcode Contains Duplicate

Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least
twice in the array, and it should return false if every element is distinct.

题意是判断整型数组里面时候有出现过两次以上的数字，有返回true，无返回false。可以先对数组进行排序，然后从前往后找是否有重复的。

class Solution {
public:
bool containsDuplicate(vector<int>& nums) {
sort(nums.begin(),nums.end());
if(nums.size()<2)
return false;
for(int i=0; i<nums.size(); i++)
{
if(nums[i]==nums[i+1])
{
return true;
}
}
return false;
}
};