【BZOJ】3065: 带插入区间K小值

#include <bits/stdc++.h>
using namespace std;

const int nTr=1000005, nSg=15000005, alphaA=4, alphaB=5;

int STop;
struct Seg *Snull;
struct Seg { Seg *l, *r; int s, cnt; }Sg[nSg], *iSg=Sg, *bin[nSg];
Seg *newS() {
	Seg *x;
	if(!STop) x=iSg++;
	else x=bin[STop--];
	x->l=x->r=Snull; x->s=0; x->cnt=1;
	return x;
}
void clean(Seg *&x) {
	if(x!=Snull && (--x->cnt==0)) {
		bin[++STop]=x;
		clean(x->l); clean(x->r);
	}
	x=Snull;
}
Seg *merge(Seg *l, Seg *r) {
	if(l==Snull) { ++r->cnt; return r; }
	if(r==Snull) { ++l->cnt; return l; }
	Seg *p=newS();
	p->l=merge(l->l, r->l);
	p->r=merge(l->r, r->r);
	p->s=l->s+r->s;
	return p;
}
Seg *ins(Seg *p, int k, int _s, int l, int r) {
	if(p->s+_s==0) { ++Snull->cnt; return Snull; }
	int mid=(l+r)>>1;
	Seg *x=newS();
	x->l=p->l; ++x->l->cnt;
	x->r=p->r; ++x->r->cnt;
	x->s=p->s+_s;
	if(l==r) return x;
	if(k<=mid) { --x->l->cnt; x->l=ins(p->l, k, _s, l, mid); }
	else { --x->r->cnt; x->r=ins(p->r, k, _s, mid+1, r); }
	return x;
}
Seg *ins(Seg *p, int k, int s) {
	Seg *x=ins(p, k, s, 0, 70000);
	clean(p);
	return x;
}
struct node *null;
struct node {
	node *c[2];
	int s, k;
	Seg *t;
	void pushup() { s=c[0]->s+c[1]->s+1; t=ins(merge(c[0]->t, c[1]->t), k, 1); }
}Tr[nTr], *iTr=Tr, *root;
node* newT(int k) {
	node *x=iTr++;
	x->s=1; x->k=k; x->c[0]=x->c[1]=null; x->t=Snull; ++Snull->cnt;
	return x;
}
node* flatten(node *x, node *y) {
	if(x==null) return y;
	clean(x->t);
	x->c[1]=flatten(x->c[1], y);
	return flatten(x->c[0], x);
}
node* build(node *x, int n) {
	if(n==0) { x->c[0]=null; return x; }
	node *y=build(x, n>>1);
	node *z=build(y->c[1], n-(n>>1)-1);
	y->c[1]=z->c[0];
	z->c[0]=y;
	y->pushup();
	return z;
}
void rebuild(node *&x) {
	static node y;
	node *head=flatten(x, &y);
	build(head, x->s);
	x=y.c[0];
}
node *rB;
void insert(node *&x, int pos, int val) {
	if(x==null) { x=newT(val); x->t=ins(Snull, val, 1); return; }
	++x->s;
	x->t=ins(x->t, val, 1);
	int s=x->c[0]->s;
	if(pos<=s) insert(x->c[0], pos, val);
	else insert(x->c[1], pos-s-1, val);
	if(max(x->c[0]->s, x->c[1]->s)*alphaB<=x->s*alphaA) { if(rB!=null) rebuild(x->c[rB==x->c[1]]), rB=null; }
	else rB=x;
}
int update(node *x, int pos, int val) {
	x->t=ins(x->t, val, 1);
	int s=x->c[0]->s+1;
	if(pos==s) swap(val, x->k);
	else if(pos<s) val=update(x->c[0], pos, val);
	else val=update(x->c[1], pos-s, val);
	x->t=ins(x->t, val, -1);
	return val;
}
struct Link {
	int len;
	struct Ln { int l, r; Seg *t; }val[nTr<<2];
	void add(Seg *x) { if(x==Snull) return; ++len; val[len].t=x; val[len].l=len-1; val[len].r=0; val[len-1].r=len; }
	void del(int x) { val[val[x].l].r=val[x].r; val[val[x].r].l=val[x].l; }
	void clr() { len=0; val[0].l=val[0].r=0; }
};
void query(node *x, int R, Link &a, Link &b) {
	if(x==null || !R) return;
	int s=x->c[0]->s+1;
	if(s<=R) a.add(x->t), b.add(x->c[1]->t), query(x->c[1], R-s, a, b);
	else query(x->c[0], R, a, b);
}
int last;
Link a, b;
void Query(int x, int y, int k) {
	a.clr(); b.clr();
	query(root, x-1, b, a);
	query(root, y, a, b);
	int l=0, r=70000;
	while(l<r) {
		x=a.val[0].r, y=b.val[0].r;
		int sum=0;
		while(x) sum+=a.val[x].t->l->s, x=a.val[x].r;
		while(y) sum-=b.val[y].t->l->s, y=b.val[y].r;
		x=a.val[0].r, y=b.val[0].r;
		if(k<=sum) {
			r=(l+r)>>1;
			while(x) { a.val[x].t=a.val[x].t->l; if(a.val[x].t==Snull) a.del(x); x=a.val[x].r; }
			while(y) { b.val[y].t=b.val[y].t->l; if(b.val[y].t==Snull) b.del(y); y=b.val[y].r; }
		}
		else {
			l=((l+r)>>1)+1;
			k-=sum;
			while(x) { a.val[x].t=a.val[x].t->r; if(a.val[x].t==Snull) a.del(x); x=a.val[x].r; }
			while(y) { b.val[y].t=b.val[y].t->r; if(b.val[y].t==Snull) b.del(y); y=b.val[y].r; }
		}
	}
	printf("%d\n", last=l);
}
void Update(int x, int val) {
	update(root, x, val);
}
void Insert(int x, int val) {
	rB=null;
	insert(root, x, val);
	if(rB!=null) rebuild(root);
}
void build(node *&x, int l, int r) {
	if(l>r) return;
	int mid=(l+r)>>1;
	x=newT(-1);
	build(x->c[0], l, mid-1);
	scanf("%d", &x->k);
	build(x->c[1], mid+1, r);
	x->pushup();
}
void init() {
	Snull=new Seg; Snull->l=Snull->r=Snull; Snull->s=0;
	null=new node; null->s=null->k=0; null->t=Snull; null->c[0]=null->c[1]=null;
	root=null;
}
int main() {
	init();
	int n, x, y, k; scanf("%d", &n);
	build(root, 1, n);
	scanf("%d", &n);
	char s[5];
	while(n--) {
		scanf("%s", s); scanf("%d%d", &x, &y); x^=last, y^=last;
		if(s[0]==‘Q‘) scanf("%d", &k), k^=last, Query(x, y, k);
		else if(s[0]==‘M‘) Update(x, y);
		else Insert(x-1, y);	
	}
	return 0;
}