poj 3468 A Simple Problem with Integers splay tree

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef long long ll;
#define Max_N 150000
#define _size(T) ((T)==null ? 0 : (T)->size)
typedef struct _spt{
	ll val, size, sum, addMark;
	struct _spt *pre, *ch[2];
}splay;
splay *null, *root, stack[Max_N];
ll sz = 0, arr[Max_N];
void pushup(splay *x){
	if (x == null) return;
	x->size = _size(x->ch[0]) + _size(x->ch[1]) + 1;
	x->sum = x->addMark + x->val + x->ch[0]->sum + x->ch[1]->sum;
}
void pushdown(splay *x){
	ll ret = 0;
	if (x == null) return;
	if (x->addMark != 0){
		ret = x->addMark;
		x->val += ret;
		if (x->ch[0] != null){
			x->ch[0]->addMark += ret;
			x->ch[0]->sum += ret * x->ch[0]->size;
		}
		if (x->ch[1] != null){
			x->ch[1]->addMark += ret;
			x->ch[1]->sum += ret * x->ch[1]->size;
		}
		x->addMark = 0;
	}
}
splay *_calloc(ll val){
	splay *p = &stack[sz++];
	p->val = p->sum = val;
	p->size = 1, p->addMark = 0;
	p->pre = p->ch[0] = p->ch[1] = null;
	return p;
}
void rotate(splay *x, int c){
	splay *y = x->pre;
	pushdown(y), pushdown(x);
	y->ch[!c] = x->ch[c];
	x->pre = y->pre;
	if (x->ch[c] != null) x->ch[c]->pre = y;
	if (y->pre != null) y->pre->ch[y->pre->ch[0] != y] = x;
	x->ch[c] = y;
	y->pre = x;
	pushup(y);
	if (y == root) root = x;
}
void splay_splay(splay *x, splay *f){
	if (x == root) return;
	for (; x->pre != f; pushdown(x)){
		if (x->pre->pre == f){
			rotate(x, x->pre->ch[0] == x);
		} else {
			splay *y = x->pre, *z = y->pre;
			if (z->ch[0] == y){
				if (y->ch[0] == x) rotate(y, 1), rotate(x, 1);
				else rotate(x, 0), rotate(x, 1);
			} else {
				if (y->ch[1] == x) rotate(y, 0), rotate(x, 0);
				else rotate(x, 1), rotate(x, 0);
			}
		}
	}
	pushup(x);
}
splay *built(ll l, ll r){
	ll mid = 0;
	splay *p = null;
	if (l > r) return null;
	mid = (l + r) >> 1;
	p = _calloc(arr[mid]);
	p->ch[0] = built(l, mid - 1);
	if (p->ch[0] != null) p->ch[0]->pre = p;
	p->ch[1] = built(mid + 1, r);
	if (p->ch[1] != null) p->ch[1]->pre = p;
	pushup(p);
	return p;
}
void initialize(ll l, ll r){
	null = _calloc(-1);
	null->size = null->sum = 0;
	root = _calloc(-1);
	root->ch[1] = _calloc(-1);
	root->ch[1]->pre = root;
	splay *x = built(l, r);
	root->ch[1]->ch[0] = x;
	x->pre = root->ch[1];
	pushup(root->ch[1]);
	pushup(root);
}
splay *select(splay *x, ll k){
	ll t = 0;
	splay *ret = x;
	for (;;){
		pushdown(ret);
		t = _size(ret->ch[0]);
		if (k == t) break;
		else if (k < t) ret = ret->ch[0];
		else k -= t + 1, ret = ret->ch[1];
	}
	return ret;
}
void get_range(ll l, ll r){
	splay_splay(select(root, l - 1), null);
	splay_splay(select(root, r + 1), root);
}
void update(ll l, ll r, ll add){
	get_range(l, r);
	splay *x = root->ch[1]->ch[0];
	x->addMark += add;
	x->sum += x->size * add;
}
void query(ll l, ll r){
	get_range(l, r);
	splay *x = root->ch[1]->ch[0];
	printf("%lld\n", x->sum);
}
int main(){
#ifdef LOCAL
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w+", stdout);
#endif
	char ch;
	ll i, a, b, c, N, Q;
	while (~scanf("%lld %lld", &N, &Q)){
		for (i = 1; i <= N; i++) scanf("%lld", &arr[i]);
		initialize(1, N);
		while (Q--){
			getchar();
			scanf("%c", &ch);
			if ('Q' == ch){
				scanf("%lld %lld", &a, &b);
				query(a, b);
			} else {
				scanf("%lld %lld %lld", &a, &b, &c);
				update(a, b, c);
			}
		}
	}
	return 0;
}