C++ 代码

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N=1e5+1e4;
ll n,ans=1;
ll a[N];
signed main()
{
  cin>>n;
  for(ll i=1; i<=n; i++)cin>>a[i];
  sort(a+1,a+n+1);
  for(ll i=2; i<=n; i++)
    if(a[i]!=a[i-1])
      ans++;
  cout<<ans;
  return 0;
}