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：
1 #include<iostream> 2 #include<cstdio> 3 #include<algorithm> 4 #include<queue> 5 #define Min(x,y) (x<y?x:y) 6 #define N 300005 7 using namespace std; 8 typedef long long LL; 9 LL n,k,t,w,rk,ans,index; 10 struct nod{ 11 LL t,w,diff; 12 nod(LL tt=0,LL ww=0){ 13 t=tt,w=ww; 14 diff=w-t; 15 } 16 bool operator < (const nod &b)const{ 17 return diff>b.diff; 18 } 19 }a[N]; 20 bool cmp(nod a,nod b){ 21 return a.t>b.t; 22 } 23 priority_queue<nod>pq; 24 int main(void){ 25 scanf("%I64d",&n); 26 scanf("%I64d%I64d",&t,&w); 27 for(LL i=1;i<n;++i){ 28 LL t,w; 29 scanf("%I64d%I64d",&t,&w); 30 if(t<=w)a[k++]=nod(t,w); 31 } 32 sort(a,a+k,cmp); 33 for(;index<k;++index){ 34 if(a[index].t<=t)break; 35 pq.push(a[index]); 36 } 37 rk=ans=index+1; 38 while(!pq.empty()){ 39 nod temp=pq.top(); 40 pq.pop(); 41 t-=temp.diff+1; 42 if(t<0)break; 43 LL i=0; 44 for(;i+index<k;++i){ 45 if(a[i+index].t<=t)break; 46 pq.push(a[i+index]); 47 } 48 rk+=i-1; 49 index+=i; 50 ans=Min(ans,rk); 51 } 52 printf("%I64d ",ans); 53 }