超时代码

#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> PII;
int n,d,k;
const int N = 100010;
int cnt[N];
PII logs[N];
set<int> us;
int main()
{
    cin >> n >> d >> k;
    for(int i = 0;i < n;i ++) scanf("%d%d",&logs[i].first,&logs[i].second);
    sort(logs,logs + n);
    for(int i = 0;i < n; i ++)
    {
        int j = i;
        unordered_map<int,int> um;
        while(j < n && logs[j].first - logs[i].first  < d)
        {
            um[logs[j].second]++;
            j++;
        }
        for(auto x : um)
        {
            if(x.second >= k)
            us.insert(x.first);
        }

    }
    for(auto x : us)
    {

        printf("%d\n",x);
    }
    return 0;
}

AC代码

#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> PII;
int n,d,k;
const int N = 100010;
int cnt[N];
PII logs[N];
bool st[N];
int main()
{
    cin >> n >> d >> k;
    for(int i = 0;i < n;i ++) scanf("%d%d",&logs[i].first,&logs[i].second);
    sort(logs,logs + n);
    for(int i = 0,j = 0;i < n;i++)
    {
        int x = logs[i].second;
        cnt[x]++;
        while(logs[i].first - logs[j].first >= d)
        {
            cnt[logs[j].second]--;
            j++;
        }
        if(cnt[x] >= k) st[x] = true;
    }
    for(int i = 0;i < 100010;i++)
    {
        if(st[i])
        printf("%d\n",i);
    }
    return 0;
}