【splay tree】 ZOJ 3765 Lights

#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 300005
#define maxm 400005
#define eps 1e-10
#define mod 1000000007
#define lowbit(x) (x&(-x))
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid
#define rson o<<1 | 1, mid+1, R
typedef long long LL;
//typedef int LL;
using namespace std;

int gcd(int a, int b)
{
if(!b) return a;
else return gcd(b, a%b);
}
struct node
{
int s, v, x, g[2];
node *ch[2], *fa;
int cmp(int x)
{
if(x == ch[0]->s + 1) return -1;
if(x > ch[0]->s + 1) return 1;
else return 0;
}
void maintain(void)
{
s = ch[0]->s + ch[1]->s + 1;
g[0] = g[1] = 0;
if(x) g[1] = gcd(g[1], v);
else g[0] = gcd(g[0], v);
g[0] = gcd(gcd(g[0], ch[0]->g[0]), ch[1]->g[0]);
g[1] = gcd(gcd(g[1], ch[0]->g[1]), ch[1]->g[1]);
}
}*null, *root, C[maxn], *top;
void rotate(node* &o, bool d)
{
node *p = o->fa; p->ch[d^1] = o->ch[d], o->fa = p->fa;
if(p->fa != null) {
if(p->fa->ch[0] == p) p->fa->ch[0] = o;
else p->fa->ch[1] = o;
}
if(p->ch[d^1] != null) p->ch[d^1]->fa = p;
p->fa = o, o->ch[d] = p;
p->maintain(), o->maintain();
}
void splay(node* &o, int k)
{
int d = o->cmp(k);
while(d != -1) {
if(d == 1) {
k -= o->ch[0]->s + 1;
o = o->ch[1];
}
else o = o->ch[0];
d = o->cmp(k);
}
node *p;
while(o->fa != null) {
p = o->fa;
if(p->ch[0] == o) {
if(p != null && p->fa->ch[0] == p)
rotate(p, true);
rotate(o, true);
}
else {
if(p != null && p->fa->ch[1] == p)
rotate(p, false);
rotate(o, false);
}
}
}
node* merge(node *left, node *right)
{
splay(left, left->s);
left->ch[1] = right;
right->fa = left;
left->maintain();
return left;
}
void split(node *o, int k, node* &left, node* &right)
{
splay(o, k);
right = o->ch[1];
right->fa = null;
o->ch[1] = null;
left = o;
left->maintain();
}
int n, m;
char s[20];

void init(void)
{
top = C;
null = top++;
null->v = null->s = null->x = 0;
null->g[0] = null->g[1] = 0;
null->ch[0] = null->ch[1] = null->fa = NULL;
root = top++;
root->v = root->s = root->x = 0;
root->ch[0] = root->ch[1] = null;
root->maintain();
}
void build(void)
{
node *p;
int v, x;
for(int i = 1; i <= n; i++) {
scanf("%d%d", &v, &x);
p = top++;
p->v = v, p->x = x;
p->ch[0] = root;
p->ch[1] = p->fa = null;
p->g[0] = p->g[1] = 0;
root->fa = p;
root = p;
root->maintain();
}
}
void work(void)
{
int k, v, x, a, b;
node *p, *mid, *left, *right;
while(m--) {
scanf("%s", s);
if(s[0] == 'M') {
scanf("%d%d", &k, &x);
splay(root, k+1);
root->v = x;
}
if(s[0] == 'R') {
scanf("%d", &k);
splay(root, k+1);
root->x^=1;
}
if(s[0] == 'Q') {
scanf("%d%d%d", &a, &b, &x);
split(root, a, left, p);
split(p, b-a+1, mid, right);
if(mid->g[x] == 0) printf("-1\n");
else printf("%d\n", mid->g[x]);
root = merge(merge(left, mid), right);
}
if(s[0] == 'I') {
scanf("%d%d%d", &k, &v, &x);
mid = top++;
mid->v = v, mid->x = x;
mid->ch[0] = mid->ch[1] = mid->fa = null;
mid->maintain();
split(root, k+1, left, right);
root = merge(merge(left, mid), right);
}
if(s[0] == 'D') {
scanf("%d", &k);
split(root, k, left, p);
split(p, 1, mid, right);
root = merge(left, right);
}
}
}
int main(void)
{
while(scanf("%d%d", &n, &m)!=EOF) {
init();
build();
work();
}
return 0;
}