BZOJ 1572 USACO 2009 Open 工作安排

先把工作按照Deadline从小到大排序

然后按顺序取，deadline大于现在总用时就取，等于现在总用时就从前面已取的工作中找一个P最小的同它比较，取P较大的一个

用优先队列维护已取工作中P的最小值

 #include<cstdio>
 #include<algorithm>
 #include<queue>
 #define LL long long
 using namespace std;
 const int maxn=;
 LL n,ans=,t=;
 struct work{
     LL d,p;
 }a[maxn];
 struct cmp1{
     bool operator() (const LL a,const LL b)const {return a>b;}
 };
 priority_queue<int,vector<int>,cmp1>q;
 void read(long long &k){
     int f=; k=; char c=getchar();
     while (c<''||c>'')c=='-'&&(f=-),c=getchar();
     while (''<=c&&c<='')k=k*+c-'',c=getchar();
     k*=f;
 }
 bool cmp2(work a,work b){return a.d<b.d;}
 int main(){
     read(n);
     for (int i=;i<=n;i++) read(a[i].d),read(a[i].p);
     sort(a+,a+n+,cmp2);
     for (int i=;i<=n;i++){
         if (a[i].d>t) q.push(a[i].p),ans+=a[i].p,t++;
         else{
             int x=q.top();
             if (x<a[i].p){
                 q.pop(); q.push(a[i].p);
                 ans+=a[i].p-x;
             }
         }
     }
     printf("%lld\n",ans);
     return ;
 }