POJ 2431 Expedition

没油瞬移回去加
为了少次数每次尽可能多加

#include <iostream>
#include <queue>

using namespace std;

const int MAXL=1000111;

int N;
int L, Now;
int Val[MAXL];
int Ans=0;
bool Flag=true;
priority_queue<int> PQ;

int main(){
	ios_base::sync_with_stdio(false);
	
	cin >> N;
	for(int i=1, d, v;i<=N;++i){
		cin >> d >> v;
		Val[d]+=v;
	}
	cin >> L >> Now;
	
	for(int i=L-1;i>=1;--i){
		if(Val[i]>0)	PQ.push(Val[i]);
		--Now;
		if(Now==0){
			if(PQ.empty()){
				Flag=false;
				break;
			}
			Now+=PQ.top();PQ.pop();
			++Ans;
		}
	}
	
	if(Flag)	cout << Ans << endl;
	else	cout << "-1" << endl;
	
	return 0;
}