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=100010;
LL n,ans=0,t=0;
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=1; k=0; char c=getchar();
    while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar();
    while ('0'<=c&&c<='9')k=k*10+c-'0',c=getchar();
    k*=f;
}
bool cmp2(work a,work b){return a.d<b.d;}
int main(){
    read(n);
    for (int i=1;i<=n;i++) read(a[i].d),read(a[i].p);
    sort(a+1,a+n+1,cmp2);
    for (int i=1;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 0;
}