题目：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.
解答说明：这个题目简直就是超级无敌太简单了好吧。在一个数组里面判断是否包含着重复元素。不说废话，贴代码了。
class Solution {
public:
bool containsDuplicate(vector<int>& nums) {
map<int,int> shownums;
for(int i = 0;i < nums.size();i++)
{
if(shownums.find(nums[i]) == shownums.end())
{
shownums[nums[i]] = 1;
}
else
{
return true;
}
}
return false;
}
};