【Codeforces #453 E】—Little Pony and Lord Tirek(线段树/均摊分析)

传送门

考虑如果每次都是全局修改就很简单
按照到达上限的时间排序
则前面一段满了,后面一段都没满
每次二分即可
第一次特殊处理

每次修改一个区间
考虑维护该区间是否上一次完全修改、不完全修改、没有修改过
如果是完全修改则直接计算答案,否则递归子树
同样特殊处理每个节点的第一次完全修改

这样复杂度是均摊O(nlog2n)O(nlog^2n)

#include<bits/stdc++.h>
using namespace std;
const int RLEN=1<<20|1;
inline char gc(){
    static char ibuf[RLEN],*ib,*ob;
    (ob==ib)&&(ob=(ib=ibuf)+fread(ibuf,1,RLEN,stdin));
    return (ob==ib)?EOF:*ib++;
}
#define gc getchar
inline int read(){
    char ch=gc();
    int res=0,f=1;
    while(!isdigit(ch))f^=ch=='-',ch=gc();
    while(isdigit(ch))res=(res+(res<<2)<<1)+(ch^48),ch=gc();
    return f?res:-res;
}
#define ll long long
#define re register
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define cs const
#define bg begin
inline void chemx(int &a,int b){a<b?a=b:0;}
inline void chemn(int &a,int b){a>b?a=b:0;}
struct node{
	int s,m,r,t;
	node(int _s=0,int _m=0,int _r=0,int _t=0):s(_s),m(_m),r(_r),t(_t){}
	friend inline bool operator <(cs node &a,cs node &b){
		return a.t<b.t;
	}
	friend inline bool operator ==(cs node &a,cs node &b){
		return a.t==b.t;
	}
	friend inline bool operator >(cs node &a,cs node &b){
		return a.t>b.t;
	}
	friend inline bool operator <=(cs node &a,cs node &b){
		return a.t<=b.t;
	}
	friend inline bool operator >=(cs node &a,cs node &b){
		return a.t>=b.t;
	}
	friend inline bool operator !=(cs node &a,cs node &b){
		return a.t!=b.t;
	}
};
cs int N=100005,inf=2e9;
node a[N];
int n,q;
struct Tr{
	vector<node> v;
	vector<ll> sl,sr;
	int last;
	inline void init(int l,int r){
		int len=r-l+1;
		for(int i=l;i<=r;i++)v.pb(a[i]);
		sort(v.bg(),v.end());
		sl.resize(len),sr.resize(len);
		sl[0]=v[0].m,sr[len-1]=v[len-1].r;
		for(int i=1;i<len;i++)sl[i]=sl[i-1]+v[i].m;
		for(int i=len-2;~i;i--)sr[i]=sr[i+1]+v[i].r;
	}
	inline ll query(int t){
		int tim=t-last;
		int pos=lower_bound(v.bg(),v.end(),node(0,0,0,tim))-v.bg()-1;
		ll res=0;
		if(~pos)res+=sl[pos];
		if(pos+1<(int)v.size())res+=sr[pos+1]*tim;
		last=t;return res;
	}
};
namespace Seg{
	Tr tr[N<<2];
	#define lc (u<<1)
	#define rc ((u<<1)|1)
	#define mid ((l+r)>>1)
	void build(int u,int l,int r){
		tr[u].last=-2,tr[u].init(l,r);
		if(l==r)return;
		build(lc,l,mid),build(rc,mid+1,r);
	}
	inline void pushup(int u){
		if(tr[lc].last==tr[rc].last)
			if(tr[lc].last>=0){tr[u].last=tr[lc].last;return;}
			else if(tr[lc].last==-2){tr[u].last=-2;return;}
		tr[u].last=-1;
	}
	inline void pushdown(int u){
		if(tr[u].last>=0)
			tr[lc].last=tr[rc].last=tr[u].last;
	}
	ll query(int u,int l,int r,int st,int des,int k){
		if(l==r&&tr[u].last==-2){tr[u].last=k;return min(1ll*a[l].m,1ll*a[l].s+1ll*a[l].r*k);}
		if(st<=l&&r<=des&&tr[u].last>=0)return tr[u].query(k);
		ll res=0;pushdown(u);
		if(st<=mid)res+=query(lc,l,mid,st,des,k);
		if(mid<des)res+=query(rc,mid+1,r,st,des,k);
		pushup(u);
		return res;
	}
}
int main(){
	n=read();
	for(int i=1;i<=n;i++){
		a[i].s=read(),a[i].m=read(),a[i].r=read(),a[i].t=a[i].r==0?inf:a[i].m/a[i].r;
	}
	Seg::build(1,1,n);
	q=read();
	while(q--){
		int t=read(),l=read(),r=read();
		cout<<Seg::query(1,1,n,l,r,t)<<'
';
	}
}
原文地址:https://www.cnblogs.com/stargazer-cyk/p/12328548.html