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.
输入一组整数,查找其中是否包含重复元素。
思路:利用unique函数和erase函数,比较去重之后的长度是否变化。如果有变化,说明有重复元素。
bool containsDuplicate(vector<int>& nums) {
int len = nums.size();
sort(nums.begin(),nums.end());
vector<int>::iterator new_end = unique(nums.begin(),nums.end());
nums.erase(new_end,nums.end());
return !(len==nums.size());
}