Contest Balloons

Contest Balloons

题目链接：http://codeforces.com/problemset/problem/725/D

贪心+枚举

每次在排名在自己前面的选出w-t值最小的送气球，更新rank即可。

（一直觉得cin比scanf不会慢太多，结果我跑出来是2000ms，队友300ms...）

代码如下：

 #include<iostream>
 #include<cstdio>
 #include<algorithm>
 #include<queue>
 #define Min(x,y) (x<y?x:y)
 #define N 300005
 using namespace std;
 typedef long long LL;
 LL n,k,t,w,rk,ans,index;
 struct nod{
     LL t,w,diff;
     nod(LL tt=,LL ww=){
         t=tt,w=ww;
         diff=w-t;
     }
     bool operator < (const nod &b)const{
         return diff>b.diff;
     }
 }a[N];
 bool cmp(nod a,nod b){
     return a.t>b.t;
 }
 priority_queue<nod>pq;
 int main(void){
     scanf("%I64d",&n);
     scanf("%I64d%I64d",&t,&w);
     for(LL i=;i<n;++i){
         LL t,w;
         scanf("%I64d%I64d",&t,&w);
         if(t<=w)a[k++]=nod(t,w);
     }
     sort(a,a+k,cmp);
     for(;index<k;++index){
         if(a[index].t<=t)break;
         pq.push(a[index]);
     }
     rk=ans=index+;
     while(!pq.empty()){
         nod temp=pq.top();
         pq.pop();
         t-=temp.diff+;
         if(t<)break;
         LL i=;
         for(;i+index<k;++i){
             if(a[i+index].t<=t)break;
             pq.push(a[i+index]);
         }
         rk+=i-;
         index+=i;
         ans=Min(ans,rk);
     }
     printf("%I64d\n",ans);
 }