BZOJ5343: [Ctsc2018]混合果汁 二分答案+主席树

分析:

整体二分或二分答案+主席树,反正没有要求强制在线,两个都可以做...

贪心还是比较显然的,那么就是找前K大的和...和CQOI的任务查询系统很像

附上代码:

#include <cstdio>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <queue>
#include <algorithm>
using namespace std;
#define N 100005
#define ll long long
#define lson l,m,tr[rt].ls
#define rson m+1,r,tr[rt].rs
struct node{int ls,rs;long long sum,siz;}tr[N*20];
struct A{int d,p,l;}a[N];
int n,Q,rot[N],cnt;
bool cmp(const A &a,const A &b){return a.d<b.d;}
void insert(int x,int v,int c,int l,int r,int &rt)
{
	rt=++cnt;tr[rt].siz=tr[x].siz+c;tr[rt].sum=tr[x].sum+1ll*v*c;if(l==r)return;int m=(l+r)>>1;
	if(v<=m)tr[rt].rs=tr[x].rs,insert(tr[x].ls,v,c,lson);else tr[rt].ls=tr[x].ls,insert(tr[x].rs,v,c,rson);
}
ll query(int x,ll k,int l,int r,int rt)
{
	// printf("%d %d %lld %lld %lld\n",l,r,k,tr[tr[x].ls].sum,tr[tr[rt].ls].sum);
	if(l==r)return k*l;int m=(l+r)>>1;ll sizls=tr[tr[rt].ls].siz-tr[tr[x].ls].siz;
	if(sizls>=k)return query(tr[x].ls,k,lson);return query(tr[x].rs,k-sizls,rson)+tr[tr[rt].ls].sum-tr[tr[x].ls].sum;
}
int check(int m,ll x,ll y)
{
	if(!m)return 0;
	if(tr[rot[100000]].siz-tr[rot[m-1]].siz<y)return 0;
	ll t1=query(rot[m-1],y,1,100000,rot[100000]);
	// printf("%d %lld\n",m,t1);
	return t1<=x;
}
int main()
{
	scanf("%d%d",&n,&Q);
	for(int i=1;i<=n;i++)scanf("%d%d%d",&a[i].d,&a[i].p,&a[i].l);sort(a+1,a+n+1,cmp);
	for(int i=1,h=1;i<=100000;i++)
	{
		rot[i]=rot[i-1];
		while(a[h].d==i)insert(rot[i],a[h].p,a[h].l,1,100000,rot[i]),h++;
	}
	while(Q--)
	{
		ll x,y;scanf("%lld%lld",&x,&y);
		int l=0,r=100001;
		while(l<r)
		{
			int m=(l+r)>>1;
			if(check(m,x,y))l=m+1;
			else r=m;
		}
		printf("%d\n",l-1);
	}
}

  

posted @ 2018-06-29 09:33  Winniechen  阅读(143)  评论(0编辑  收藏  举报