Contains Duplicate 重复数的判断

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.

class Solution {
public:
//看是否有重复
    bool containsDuplicate(vector<int>& nums) {
        
        int len=nums.size();
        if(len<=1)//0个1个都false
            return false;
        sort(nums.begin(),nums.end());
        int f=0;
        for(int i=0;i<len-1;i++)
            if(nums[i]==nums[i+1]){
                f=1;
                break;
            }
        if(f==1)
            return true;
        else
            return false;
    }
};