用结构体存每一个帖子被点赞的时间，因为数据给的是乱序的，所以在查找前给每一个帖子所代表的vector升序排序，并开始查找，如果点赞数大于等于K就break并输出该帖子的id

#include <bits/stdc++.h>

using namespace std;
const int N = 1e5 + 10;
struct node{
    vector<int> v;
};
node arr[N];
int main()
{
    int n , t , k;
    scanf("%d %d %d"  ,&n , &t , &k);
    int minn = INT_MAX , maxx = INT_MIN; 
    for (int i = 1 ; i <= n ; i++)
    {
        int a , b;
        scanf("%d %d" , &a , &b);
        arr[b].v.push_back(a);
        minn = min(minn , b);
        maxx = max(maxx , b);
    }
    for (int i = minn ; i <= maxx ; i++) 
    {
        if (arr[i].v.size())
        {
            sort(arr[i].v.begin() , arr[i].v.end());
            int tag = 0;
            for (int j = 0 ; j < arr[i].v.size() ; j++)
            {
                int ret = arr[i].v[j];
                int num = 1;
                for (int p = j + 1 ; arr[i].v[p] < ret + t && p < arr[i].v.size() ; p++) num++;
                if (num >= k)
                {
                    tag = 1;break;
                }
            }
            if (tag) cout << i << endl;
        }
    }
    return 0;
}