POJ 3622 multiset

思路：
放一个链接

是我太懒了
http://blog.csdn.net/mars_ch/article/details/52835978
嗯她教的我（姑且算是吧）
（一通乱搞就出来了…）

//By SiriusRen#include <set>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;#define N 100500int n,m,id=1;long long ans;struct Node{int a,b;}cow[N],grass[N];bool cmp(Node a,Node b){return a.b>b.b;}multiset<int>s;multiset<int>::iterator it;int main(){    scanf("%d%d",&n,&m);    for(int i=1;i<=n;i++)        scanf("%d%d",&cow[i].a,&cow[i].b);    for(int i=1;i<=m;i++)        scanf("%d%d",&grass[i].a,&grass[i].b);    sort(cow+1,cow+1+n,cmp),sort(grass+1,grass+1+m,cmp);    for(int i=1;i<=n;i++){        while(grass[id].b>=cow[i].b)s.insert(grass[id].a),id++;        it=s.lower_bound(cow[i].a);        if(it==s.end()){puts("-1");return 0;}        ans+=*it;        s.erase(it);    }    printf("%lld\n",ans);}