# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
743152 | 2023-05-17T08:23:52 Z | vjudge1 | Lightning Rod (NOI18_lightningrod) | C++17 | 0 ms | 0 KB |
#include <iostream> #include <unordered_map> using namespace std; inline void read(long long &x) { x = 0; char ch = getchar_unlocked(); while (ch & 16) { x = (x << 3) + (x << 1) + (ch & 15); ch = getchar_unlocked(); } } int main () { unordered_map<int,int> m; long long n, a, b, sum = 0; read(n); for(long long i = 0;i < n;++i) { read(a); read(b); if(ma[a] == 0) { ma[a] = 1; sum++; } } cout << sum; }