【比赛】HNOI2018 游戏

考试的时候线段树区间查询的return条件打成了l==r。。。。于是光荣爆20（线段树都不会打了？）

看膜博士的题解

#include<bits/stdc++.h>
#define ui unsigned int
#define ll long long
#define db double
#define ld long double
#define ull unsigned long long
const int MAXN=1000000+10,inf=0x3f3f3f3f;
int n,m,p,lmtL[MAXN],lmtR[MAXN],L[MAXN],R[MAXN],key[MAXN],stack[MAXN],cnt;
template<typename T> inline void read(T &x)
{
	T data=0,w=1;
	char ch=0;
	while(ch!='-'&&(ch<'0'||ch>'9'))ch=getchar();
	if(ch=='-')w=-1,ch=getchar();
	while(ch>='0'&&ch<='9')data=((T)data<<3)+((T)data<<1)+(ch^'0'),ch=getchar();
	x=data*w;
}
template<typename T> inline void write(T x,char ch='\0')
{
	if(x<0)putchar('-'),x=-x;
	if(x>9)write(x/10);
	putchar(x%10+'0');
	if(ch!='\0')putchar(ch);
}
template<typename T> inline void chkmin(T &x,T y){x=(y<x?y:x);}
template<typename T> inline void chkmax(T &x,T y){x=(y>x?y:x);}
template<typename T> inline T min(T x,T y){return x<y?x:y;}
template<typename T> inline T max(T x,T y){return x>y?x:y;}
#define Mid ((l+r)>>1)
#define ls rt<<1
#define rs rt<<1|1
#define lson ls,l,Mid
#define rson rs,Mid+1,r
struct Segment_Tree{
	int Mx[MAXN<<2];
	inline void PushUp(int rt)
	{
		Mx[rt]=max(Mx[ls],Mx[rs]);
	}
	inline void Build(int rt,int l,int r)
	{
		if(l==r)Mx[rt]=key[l];
		else Build(lson),Build(rson),PushUp(rt);
	}
	inline int Mxquery(int rt,int l,int r,int k)
	{
		if(Mx[rt]<=k)return 0;
		if(l==r)return l;
		else
		{
			if(Mx[rs]>k)return Mxquery(rson,k);
			else return Mxquery(lson,k);
		}
	}
	inline int Psquery(int rt,int l,int r,int L,int R,int k)
	{
		if(L<=l&&r<=R)return Mxquery(rt,l,r,k);
		int res=0;
		if(R>Mid)res=Psquery(rson,L,R,k);
		if(res)return res;
		if(L<=Mid)res=Psquery(lson,L,R,k);
		return res;
	}
	inline int Query(int L,int R,int k)
	{
		if(R<L)return L;
		int res=Psquery(1,1,n,L,R,k);
		return res?res+1:L;
	}
};
Segment_Tree T;
#undef Mid
#undef ls
#undef rs
#undef lson
#undef rson
inline void init()
{
	T.Build(1,1,n);
	for(register int i=1;i<=n;++i)
		if(key[i-1]&&key[i-1]<=i-1)lmtL[i]=i;
		else lmtL[i]=lmtL[i-1];
	for(register int i=n;i>=1;--i)
		if(key[i]&&key[i]>i)lmtR[i]=i;
		else lmtR[i]=lmtR[i+1];
	for(register int i=n;i>=1;--i)
	{
		L[i]=R[i]=i;
		L[i]=T.Query(lmtL[i],L[i]-1,R[i]);
		stack[++cnt]=i;
		while(cnt&&((L[i]<=key[stack[cnt]]&&key[stack[cnt]]<=R[i])||(!key[stack[cnt]])))
		{
			R[i]=stack[--cnt];
			L[i]=T.Query(lmtL[i],L[i]-1,R[i]);
		}
	}
}
int main()
{
	freopen("game.in","r",stdin);
	freopen("game.out","w",stdout);
	read(n);read(m);read(p);
	for(register int i=1;i<=m;++i)
	{
		int x,y;
		read(x);read(y);
		key[x]=y;
	}
	key[0]=-inf,key[n]=inf;
	init();
	while(p--)
	{
		int s,t;
		read(s);read(t);
		if(L[s]<=t&&t<=R[s])puts("YES");
		else puts("NO");
	}
	return 0;
}