【BZOJ】2333: [SCOI2011]棘手的操作

#include <bits/stdc++.h>
using namespace std;
const int N=300015, Lim=N;
struct node *null;
struct node {
	node *c[2], *f;
	int s, tag, mx, w;
	void init(int _w=-(~0u>>2)) { c[0]=c[1]=f=null; s=1; tag=0; mx=w=_w; }
	void up() { if(this==null) return; s=c[0]->s+c[1]->s+1; mx=max(w, max(c[0]->mx, c[1]->mx)); }
	void upd(int add) { if(this==null) return; mx+=add; w+=add; tag+=add; }
	void down() { if(tag) c[0]->upd(tag), c[1]->upd(tag), tag=0; }
	bool d() { return f->c[1]==this; }
	void setc(node *x, int d) { c[d]=x; x->f=this; }
}Po[Lim], *iT=Po, *p[N];
node *newnode(int w=-(~0u>>2)) { iT->init(w); return iT++; }
void rot(node *x) {
	node *f=x->f; f->down(); x->down(); bool d=x->d();
	if(f->f!=null) f->f->setc(x, f->d());
	else x->f=f->f;
	f->setc(x->c[!d], d);
	x->setc(f, !d);
	f->up();
}
void splay(node *x, node *goal) {
	if(x==null) return;
	while(x->f!=goal)
		if(x->f->f==goal) rot(x);
		else x->d()==x->f->d()?(rot(x->f), rot(x)):(rot(x), rot(x));
	x->up();
}
int getrank(node *x) { splay(x, null); return x->c[0]->s; }
node *sel(int k, node *x) {
	int s=x->c[0]->s;
	if(s==k) return x;
	if(s<k) return sel(k-s-1, x->c[1]);
	return sel(k, x->c[0]);
}
node *sel(int k) { splay(&Po[1], null); return sel(k, &Po[1]); }
node *getrange(int l, int r) {
	node *nl=sel(l-1), *nr=sel(r+1);
	splay(nl, null); splay(nr, nl); return nr;
}
node *getblc(node *x, int len) { int rk=getrank(x); return getrange(rk, rk+len-1); }

int pf[N], sz[N], wsum, a[N], n;
int find(int x) { return pf[x]==x?x:pf[x]=find(pf[x]); }
void U(int x, int y) {
	int fx=find(x), fy=find(y);
	if(fx==fy) return;
	if(sz[fx]<sz[fy]) swap(x, y), swap(fx, fy);
	sz[fx]+=sz[fy]; pf[fy]=fx;
	node *yf=getblc(p[fy], sz[fy]), *ny=yf->c[0];
	// printf("%d, %d\n", yf, ny);
	yf->c[0]=null; ny->f=null;
	splay(yf, null);
	splay(p[fx], null);
	splay(sel(p[fx]->c[0]->s+1), p[fx]);
	p[fx]->c[1]->setc(ny, 0);
	splay(ny, null);
}
void A1(int x, int v) { splay(p[x], null); p[x]->w+=v; p[x]->up(); }
void A2(int x, int v) { x=find(x); node *y=getblc(p[x], sz[x]); y->c[0]->upd(v); splay(y->c[0], null); }
void A3(int v) { wsum+=v; }
int F1(int x) { splay(p[x], null); return p[x]->w; }
int F2(int x) { int rt=find(x); node *y=getblc(p[rt], sz[rt]); return y->c[0]->mx; }
int F3() { splay(&Po[1], null); return Po[1].mx; }
node *build(int l, int r) {
	if(l>r) return null;
	int mid=(l+r)>>1;
	node *x=p[mid]=newnode(a[mid]), *nl=build(l, mid-1), *nr=build(mid+1, r);
	if(nl!=null) x->setc(nl, 0);
	if(nr!=null) x->setc(nr, 1);
	x->up();
	return x;
}
void init() {
	null=iT++; null->init(); null->s=0;
	node *l=newnode(), *r=newnode();
	l->setc(r, 1);
	r->setc(build(1, n), 0);
	r->up(); l->up();
	//D(l);
	for(int i=1; i<=n; ++i) pf[i]=i, sz[i]=1;
}
int main() {
	scanf("%d", &n);
	for(int i=1; i<=n; ++i) scanf("%d", &a[i]);
	init();
	int Q; scanf("%d", &Q);
	while(Q--) {
		char cs[5];
		int x, v;
		scanf("%s", cs);
		if(cs[0]==‘A‘) {
			if(cs[1]==‘1‘) scanf("%d%d", &x, &v), A1(x, v);
			else if(cs[1]==‘2‘) scanf("%d%d", &x, &v), A2(x, v);
			else scanf("%d", &v), A3(v);
		}
		else if(cs[0]==‘U‘) scanf("%d%d", &x, &v), U(x, v);
		else {
			int ans;
			if(cs[1]==‘1‘) scanf("%d", &x), ans=F1(x);
			else if(cs[1]==‘2‘) scanf("%d", &x), ans=F2(x);
			else ans=F3();
			printf("%d\n", ans+wsum);
		}
		//puts("");
		//splay(&Po[1], null);
		//D(&Po[1]);
	}
	return 0;
}