习题册（堆）

习题册

好菜，这个的全名我都不知道，只知其意。

priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> h[4];
//最开始写的h[3],想的是只分为1,2,3个堆;
//但是报错了！！
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc

到现在也不清楚为什么要开四个，难道堆也是h[0]、h[1]、h[2]、h[3]

#include<bits/stdc++.h>
using namespace std;

const int N  = 2e5 + 10;

struct node{
    int p, a, b;
}a[N];

priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> h[4];
int n, m;
int st[N];

int main(){

    std::ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    cin >> n;
    for(int i = 1; i <= n; i ++) cin >> a[i].p;
    for(int i = 1; i <= n; i ++) cin >> a[i].a;
    for(int i = 1; i <= n; i ++) cin >> a[i].b;

    for(int i = 1; i <= n; i ++) {
        h[a[i].a].push({a[i].p, i});
        h[a[i].b].push({a[i].p, i});
    }

    cin >> m;
    while(m--){
        int x;
        cin >> x;
        int flag = 0;
        if(h[x].size()){
            while(h[x].size()){
                if(st[h[x].top().second]) h[x].pop();//其他堆里面需要判断
                else{
                    cout << h[x].top().first << " ";
                    st[h[x].top().second] = 1;
                    h[x].pop();
                    flag = 1;
                    break;
                }
            }
        }
        if(flag == 0) cout << -1 << " ";
    }

}