217 Contains Duplicate

原题描述

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.

分析

最容易想到的就是利用map

代码示例

class Solution {public:    bool containsDuplicate(vector<int>& nums) {        map<int, bool> record;        for(vector<int>::iterator i = nums.begin(); i != nums.end(); i++)        {            if(record.find(*i) == record.end())                record[*i] = true;            else                return true;        }        return false;    }};