[题解]LuoGu3178：[HAOI2015]树上操作

原题传送门
我又双叒叕来水博客啦
我说了这句话说明我是真的来水的~
刷刷熟练度
单点修改+子树修改都是区间修改（单点当成区间）
查询就是跳根啦

注意：全部开longlong！虽然我不知道为什么要全开，我部分开longlong50分，全开就过了

Code：

#include <bits/stdc++.h>
#define maxn 100010
#define ls rt << 1
#define rs rt << 1 | 1
#define LL long long
#define int long long
using namespace std;
struct Edge{
	int to, next;
}edge[maxn << 1];
struct Seg{
	int l, r;
	LL tag, sum;
}seg[maxn << 2];
int head[maxn], num, d[maxn], fa[maxn], size[maxn], son[maxn];
int id[maxn], cnt, top[maxn], a[maxn], w[maxn], n, m;

inline int read(){
	int s = 0, w = 1;
	char c = getchar();
	for (; !isdigit(c); c = getchar()) if (c == '-') w = -1;
	for (; isdigit(c); c = getchar()) s = (s << 1) + (s << 3) + (c ^ 48);
	return s * w;
}

void add_edge(int x, int y){ edge[++num].to = y; edge[num].next = head[x]; head[x] = num; }

void dfs(int u){
	size[u] = 1, son[u] = -1;
	for (int i = head[u]; i; i = edge[i].next){
		int v = edge[i].to;
		if (v != fa[u]){
			fa[v] = u, d[v] = d[u] + 1;
			dfs(v);
			size[u] += size[v];
			if (son[u] == -1 || son[u] != -1 && size[son[u]] < size[v]) son[u] = v;
		}
	}
}

void dfs(int u, int x){
	id[u] = ++cnt, top[u] = x, w[cnt] = a[u];
	if (son[u] == -1) return;
	dfs(son[u], x);
	for (int i = head[u]; i; i = edge[i].next){
		int v = edge[i].to;
		if (v != fa[u] && v != son[u]) dfs(v, v);
	}
}

void pushup(int rt){ seg[rt].sum = seg[ls].sum + seg[rs].sum; }

void pushdown(int rt){
	seg[ls].sum += (seg[ls].r - seg[ls].l + 1) * seg[rt].tag;
	seg[rs].sum += (seg[rs].r - seg[rs].l + 1) * seg[rt].tag;
	seg[ls].tag += seg[rt].tag;
	seg[rs].tag += seg[rt].tag;
	seg[rt].tag = 0;
}

void build(int rt, int l, int r){
	seg[rt].l = l, seg[rt].r = r;
	if (l == r){
		seg[rt].sum = w[l]; return;
	}
	int mid = (l + r) >> 1;
	build(ls, l, mid); build(rs, mid + 1, r);
	pushup(rt);
}

void update(int rt, int l, int r, int delta){
	if (seg[rt].l > r || seg[rt].r < l) return;
	if (seg[rt].l >= l && seg[rt].r <= r){
		seg[rt].sum += (seg[rt].r - seg[rt].l + 1) * delta;
		seg[rt].tag += delta;
		return;
	}
	pushdown(rt);
	update(ls, l, r, delta); update(rs, l, r, delta);
	pushup(rt);
}

LL query(int rt, int l, int r){
	if (seg[rt].l > r || seg[rt].r < l) return 0;
	if (seg[rt].l >= l && seg[rt].r <= r) return seg[rt].sum;
	pushdown(rt);
	return query(ls, l, r) + query(rs, l, r);
}

signed main(){
	n = read(), m = read();
	for (int i = 1; i <= n; ++i) a[i] = read();
	for (int i = 1; i < n; ++i){
		int x = read(), y = read();
		add_edge(x, y); add_edge(y, x);
	}
	dfs(1); dfs(1, 1); build(1, 1, n);
	while (m--){
		int opt = read();
		if (opt == 1){
			int x = read(), y = read();
			update(1, id[x], id[x], y);
		} else
		if (opt == 2){
			int x = read(), y = read();
			update(1, id[x], id[x] + size[x] - 1, y);
		} else{
			int x = read(); LL ans = 0;
			while (top[x] != 1){
				ans += query(1, id[top[x]], id[x]);
				x = fa[top[x]];
			}
			ans += query(1, id[top[x]], id[x]);
			printf("%lld\n", ans);
		}
	}
	return 0;
}