BZOJ1029: [JSOI2007]建筑抢修(贪心)

题目链接：BZOJ1029: [JSOI2007]建筑抢修

题解：贪心思想，按结束时间从小到大排序，选花费时间尽量短的建筑维修，用堆维护。

 #include<stdio.h>
 #include<queue>
 #include<algorithm>
 using namespace std;
 const int N = ;
 struct node{
     int t1, t2;
 }s[N];

 int cmp(node a, node b){
     return a.t2 < b.t2;
 }

 int main(){
     int n, t1, t2, i, cur;
     scanf("%d", &n);
     for(i = ; i < n; ++i)
         scanf("%d %d", &s[i].t1, &s[i].t2);
     sort(s, s+n, cmp);
     priority_queue<int>q;
     for(cur = i = ; i < n; ++i){
         if(cur + s[i].t1 < s[i].t2){
             q.push(s[i].t1);
             cur += s[i].t1;
         }
         else if(!q.empty()&& s[i].t1 < q.top()){
             cur = cur -q.top() + s[i].t1;
             q.pop();
             q.push(s[i].t1);
         }
     }
     printf("%d\n", q.size());
     return ;
 }