hdu 5360 Hiking

思路：贪心。ans为现在已经邀请到的人数，则下一位应该邀请的人应该为符合条件的人（li<=ans<=r）中r最小的，可以用一个优先队列来维护（li<=ri)中r最小的人。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<string>
#include<algorithm>
#include<queue>
#include<vector>
#include<cmath>
#define N 1000005
#define M 1000005
#define LL long long
#define mod 1000000007
#define INF 0x3f3f3f3f
using namespace std;

int n;

struct node{
	int r, id;
	node(){}
	node(int _r, int _id){
		r = _r, id = _id;
	}
	bool operator < (const node &o) const{
		return r > o.r;
	}
};

int a[N];
int b[N];
bool vis[N];
vector<node> v[N];
priority_queue<node> q;

void init(){
	memset(vis, false, sizeof vis);
	for (int i = 0; i <= n; i++)
		v[i].clear();
	scanf("%d", &n);
	for (int i = 1; i <= n; i++)
		scanf("%d", &a[i]);
	for (int i = 1; i <= n; i++){
		int x;
		scanf("%d", &x);
		v[a[i]].push_back(node(x, i));
	}
}

void solve(){
	int ans = 0;
	while (1){
		for (int i = 0; i < v[ans].size(); i++){
			q.push(v[ans][i]);
		}
		node temp;
		bool flag = false;
		while (!q.empty()){
			temp = q.top();
			q.pop();
			if (ans <= temp.r){
				ans++;
				b[ans] = temp.id;
				vis[temp.id] = true;
				flag = true;
				break;
			}
		}
		if (!flag)break;
	}
	int k = ans++;
	for (int i = 1; i <= n; i++){
		if (!vis[i]){
			b[ans++] = i;
		}
	}
	printf("%d\n", k);
	for (int i = 1; i <= n; i++){
		if (i == n)printf("%d\n", b[i]);
		else printf("%d ", b[i]);
	}
	return;
}


int main(){
	int t;
	cin >> t;
	while (t--){
		init();
		solve();
	}
	return 0;
}