1029: [JSOI2007]建筑抢修

#include
#include
#include
#define a first
#define b second
using namespace std;
inline int read(){  
    int x=0,f=1;char ch=getchar();  
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}  
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}  
    return x*f;  
}  
pair t[150001];
priority_queue q;
int n,now,ans;
int main(){
	n=read();
	for(int i=1;i<=n;i++)
		t[i].b=read(),t[i].a=read();
	sort(t+1,t+n+1);
	for(int i=1;i<=n;i++){
		if(now+t[i].b<=t[i].a){
			now+=t[i].b;
			q.push(t[i].b);
			ans++;
		}
		else if(t[i].b