I was solving a simple problem of finding unique elements in an array. I used a std::unordered_map to count unique elements but it gave Time Limit Exceeded in one test case. Then I used a std::unordered_set with the same result.
PS: I used std::unordered_map and std::unordered_set because I read that these two are much much faster than std::map and std::set respectively.
#include<bits/stdc++.h>
using namespace std;
int main() {
int n, a;
cin >> n;
unordered_set<int> s;
for(int i = 0; i < n; i++) {
cin >> a;
s.insert(a);
}
cout << s.size();
}
测试7超过了时间限制。
我的问题是：
If std::unordered_map and std::unordered_set are faster why did they give TLE?
