(暴力枚举)

C++ 代码

#include <bits/stdc++.h>

using namespace std;
const int N = 1e5 + 10;
set<int> res;
int n,D,K;
vector<int> Time[N];

int main()
{
    cin >> n >> D >> K;

    for(int i = 0 ; i < n ; i++)
    {
        int ts,id;
        cin >> ts >> id;
        Time[ts].push_back(id); 
    }

    map<int,int> current;
    for(int i = 0 ; i < D ; i++ )
        for(auto u : Time[i])
            current[u]++;

    for(int i = D ; i < N ; i++)
    {
        for(auto u : Time[i-D])
        {
            if(current[u]>=K)   res.insert(u);
            current[u]--;
        }

        for(auto u : Time[i])
            current[u]++;
    }

    for(auto u : current)
        if(u.second>=K) res.insert(u.first);

    for(auto u : res)
        cout << u << endl; 

    return 0;
}