BZOJ4695:最假女选手

浅谈区间最值操作和历史最值问题:https://www.cnblogs.com/AKMer/p/10225100.html

题目传送门:https://lydsy.com/JudgeOnline/problem.php?id=4695

吉司机线段树板子大集合。所有信息都封装在一个结构体里会比开多个数组快14秒。

注意暴力(dfs)子树时要(pushdown)

时间复杂度:(O(nlog^2n))

空间复杂度:(O(n))

代码如下:

#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long ll;

const int maxn=5e5+5,inf=1e9;

int n,m;
int a[maxn];

inline int read() {
	int x=0,f=1;char ch=getchar();
	for(;ch<'0'||ch>'9';ch=getchar())if(ch=='-')f=-1;
	for(;ch>='0'&&ch<='9';ch=getchar())x=x*10+ch-'0';
	return x*f;
}

struct segment_tree {
	struct tree_node {
		ll sum;
		int cntA,cntZ,tag,A,B,Y,Z;//A最大值,B严格次大值,Y严格次小值,Z最小值
	}tree[maxn<<2];

	inline void update(int p) {
		tree[p].A=max(tree[p<<1].A,tree[p<<1|1].A);
		tree[p].Z=min(tree[p<<1].Z,tree[p<<1|1].Z);
		tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
		tree[p].cntA=(tree[p<<1].A==tree[p].A)*tree[p<<1].cntA;
		tree[p].cntA+=(tree[p<<1|1].A==tree[p].A)*tree[p<<1|1].cntA;
		tree[p].cntZ=(tree[p<<1].Z==tree[p].Z)*tree[p<<1].cntZ;
		tree[p].cntZ+=(tree[p<<1|1].Z==tree[p].Z)*tree[p<<1|1].cntZ;
		tree[p].B=tree[p<<1|1].A!=tree[p].A?tree[p<<1|1].A:tree[p<<1|1].B;
		tree[p].B=max(tree[p].B,tree[p<<1].A!=tree[p].A?tree[p<<1].A:tree[p<<1].B);
		tree[p].Y=tree[p<<1|1].Z!=tree[p].Z?tree[p<<1|1].Z:tree[p<<1|1].Y;
		tree[p].Y=min(tree[p].Y,tree[p<<1].Z!=tree[p].Z?tree[p<<1].Z:tree[p<<1].Y);
	}
	
	inline void build(int p,int l,int r) {
		if(l==r) {
			tree[p].cntA=tree[p].cntZ=1;
			tree[p].sum=tree[p].A=tree[p].Z=a[l];
			tree[p].B=-inf,tree[p].Y=inf;
			return;
		}
		int mid=(l+r)>>1;
		build(p<<1,l,mid);
		build(p<<1|1,mid+1,r);
		update(p);
	}
	
	inline void add_tag(int p,int l,int r,int v) {
        tree[p].A+=v,tree[p].Z+=v,tree[p].tag+=v;
        if(tree[p].Y!=inf)tree[p].Y+=v;
        if(tree[p].B!=-inf)tree[p].B+=v;
        tree[p].sum+=1ll*(r-l+1)*v;
    }

	inline void max_tag(int p,int v) {
		tree[p].sum+=1ll*tree[p].cntZ*(v-tree[p].Z),tree[p].Z=v;
		if(tree[p].Y==inf)tree[p].A=v;
		else tree[p].B=max(tree[p].B,v);
	}

	inline void min_tag(int p,int v) {
		tree[p].sum-=1ll*tree[p].cntA*(tree[p].A-v),tree[p].A=v;
		if(tree[p].B==-inf)tree[p].Z=v;
		else tree[p].Y=min(tree[p].Y,v);
	}

	inline void solveMax(int p,int l,int r,int limit) {
		if(limit<=tree[p].Z)return;
		if(limit>tree[p].Z&&limit<tree[p].Y) {
			max_tag(p,limit);
			return;
		}
		int mid=(l+r)>>1;push_down(p,l,r);
		solveMax(p<<1,l,mid,limit);
		solveMax(p<<1|1,mid+1,r,limit);
		update(p);
	}

	inline void solveMin(int p,int l,int r,int limit) {
		if(limit>=tree[p].A)return;
		if(limit<tree[p].A&&limit>tree[p].B) {
			min_tag(p,limit);
			return;
		}
		int mid=(l+r)>>1;push_down(p,l,r);
		solveMin(p<<1,l,mid,limit);
		solveMin(p<<1|1,mid+1,r,limit);
		update(p);
	}

	inline void push_down(int p,int l,int r) {
		int mid=(l+r)>>1;
		if(tree[p].tag) {
			add_tag(p<<1,l,mid,tree[p].tag);
			add_tag(p<<1|1,mid+1,r,tree[p].tag);
			tree[p].tag=0;
		}
		solveMin(p<<1,l,mid,tree[p].A);
		solveMin(p<<1|1,mid+1,r,tree[p].A);
		solveMax(p<<1,l,mid,tree[p].Z);
		solveMax(p<<1|1,mid+1,r,tree[p].Z);
	}

	inline void ADD(int p,int l,int r,int L,int R,int v) {
		if(L<=l&&r<=R) {
			add_tag(p,l,r,v);
			return;
		}
		int mid=(l+r)>>1;push_down(p,l,r);
		if(L<=mid)ADD(p<<1,l,mid,L,R,v);
		if(R>mid)ADD(p<<1|1,mid+1,r,L,R,v);
		update(p);
	}

	inline void MAX(int p,int l,int r,int L,int R,int v) {
		if(tree[p].Z>=v)return;
		if(L<=l&&r<=R) {
			solveMax(p,l,r,v);
			return;
		}
		int mid=(l+r)>>1;push_down(p,l,r);
		if(L<=mid)MAX(p<<1,l,mid,L,R,v);
		if(R>mid)MAX(p<<1|1,mid+1,r,L,R,v);
		update(p);
	}

	inline void MIN(int p,int l,int r,int L,int R,int v) {
		if(tree[p].A<=v)return;
		if(L<=l&&r<=R) {
			solveMin(p,l,r,v);
			return;
		}
		int mid=(l+r)>>1;push_down(p,l,r);
		if(L<=mid)MIN(p<<1,l,mid,L,R,v);
		if(R>mid)MIN(p<<1|1,mid+1,r,L,R,v);
		update(p);
	}

	inline ll querySum(int p,int l,int r,int L,int R) {
		if(L<=l&&r<=R)return tree[p].sum;
		int mid=(l+r)>>1;ll res=0;push_down(p,l,r);
		if(L<=mid)res=querySum(p<<1,l,mid,L,R);
		if(R>mid)res+=querySum(p<<1|1,mid+1,r,L,R);
		return res;
	}

	inline int queryMax(int p,int l,int r,int L,int R) {
		if(L<=l&&r<=R)return tree[p].A;
		int mid=(l+r)>>1,res=-inf;push_down(p,l,r);
		if(L<=mid)res=max(res,queryMax(p<<1,l,mid,L,R));
		if(R>mid)res=max(res,queryMax(p<<1|1,mid+1,r,L,R));
		return res;
	}

	inline int queryMin(int p,int l,int r,int L,int R) {
		if(L<=l&&r<=R)return tree[p].Z;
		int mid=(l+r)>>1,res=inf;push_down(p,l,r);
		if(L<=mid)res=min(res,queryMin(p<<1,l,mid,L,R));
		if(R>mid)res=min(res,queryMin(p<<1|1,mid+1,r,L,R));
		return res;
	}
}T;

int main() {
	n=read();
	for(int i=1;i<=n;i++)
		a[i]=read();
	T.build(1,1,n);
	m=read();
	for(int i=1;i<=m;i++) {
		int opt=read(),l=read(),r=read(),v=(opt<4?read():0);
		if(opt==1)T.ADD(1,1,n,l,r,v);
		if(opt==2)T.MAX(1,1,n,l,r,v);
		if(opt==3)T.MIN(1,1,n,l,r,v);
		if(opt==4)printf("%lld
",T.querySum(1,1,n,l,r));
		if(opt==5)printf("%d
",T.queryMax(1,1,n,l,r));
		if(opt==6)printf("%d
",T.queryMin(1,1,n,l,r));
	}
	return 0;
}
原文地址:https://www.cnblogs.com/AKMer/p/10229045.html