#include <bits/stdc++.h>
#include <ranges>
namespace ra = std::ranges;
namespace vi = std::ranges::views;
using namespace std;

auto containsDuplicate(vector<int>& nums) -> bool
{
	return unordered_set(nums.begin(), nums.end()).size() != nums.size();
}

auto main() -> int
{
	auto nums = vector{ 1,2,3,1 };
	cout << boolalpha<< containsDuplicate(nums) << endl;
	nums = vector{1,2,3,4};
	cout << boolalpha<< containsDuplicate(nums) << endl;
	nums = vector{1,1,1,3,3,4,3,2,4,2};
	cout << boolalpha<< containsDuplicate(nums) << endl;
	return 0;
}