# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
743152 | vjudge1 | Lightning Rod (NOI18_lightningrod) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#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;
}