1 struct Tree
2 {
3 int n, a[maxn];
4
5 struct Edge
6 {
7 int v, next;
8 }edge[maxn<<1];
9
10 int head[maxn], tot;
11
12 void add(int u, int v)
13 {
14 edge[tot].v = v;
15 edge[tot].next = head[u];
16 head[u] = tot++;
17 }
18
19 int fa[maxn], deep[maxn], son[maxn], size[maxn];
20 int top[maxn], id[maxn], rk[maxn];
21 int cnt;
22
23 void dfs1(int x, int pre, int d)
24 {
25 size[x] = 1, deep[x] = d, fa[x] = pre;
26 for (int i = head[x]; i != -1; i = edge[i].next)
27 {
28 int v = edge[i].v;
29 if (v == pre) continue;
30 dfs1(v, x, d + 1);
31 size[x] += size[v];
32 if (size[v] > size[son[x]]) son[x] = v;
33 }
34 }
35
36 void dfs2(int x, int tp)
37 {
38 top[x] = tp, id[x] = ++cnt, rk[cnt] = x;
39 if (son[x]) dfs2(son[x], tp);
40 for (int i = head[x]; i != -1; i = edge[i].next)
41 {
42 int v = edge[i].v;
43 if (v == fa[x] || v == son[x]) continue;
44 dfs2(v, v);
45 }
46 }
47
48 int sum[maxn << 2], lazy[maxn << 2];
49
50 void push_up(int rt)
51 {
52 sum[rt] = (sum[ls] + sum[rs]);
53 }
54
55 void push_down(int rt,int l,int r)
56 {
57 int mid = (l + r) >> 1;
58 sum[ls] += lazy[rt] * (mid - l + 1);
59 sum[rs] += lazy[rt] * (r - mid);
60 lazy[ls] += lazy[rt];
61 lazy[rs] += lazy[rt];
62 lazy[rt] = 0;
63 }
64
65 void build(int rt, int l, int r)
66 {
67 if (l == r)
68 {
69 sum[rt] = a[rk[l]];
70 return;
71 }
72 int mid = (l + r) >> 1;
73 build(ls,l,mid);
74 build(rs,mid+1,r);
75 push_up(rt);
76 }
77
78 void update(int rt, int l, int r, int ql, int qr, int val)
79 {
80 if (ql <= l && qr >= r)
81 {
82 lazy[rt] += val;
83 sum[rt] += val * (r - l + 1);
84 return;
85 }
86 push_down(rt, l, r);
87 int mid = (l + r) >> 1;
88 if (ql <= mid) update(ls, l, mid, ql, qr, val);
89 if (qr > mid) update(rs, mid + 1, r, ql, qr, val);
90 push_up(rt);
91 }
92
93 int query(int rt, int l, int r, int ql, int qr)
94 {
95 if (ql <= l && qr >= r)
96 {
97 return sum[rt];
98 }
99 push_down(rt, l, r);
100 int mid = (l + r) >> 1;
101 int res = 0;
102 if (ql <= mid) res += query(ls, l, mid, ql, qr);
103 if (qr > mid) res += query(rs, mid + 1, r, ql, qr);
104 return res;
105 }
106
107 int getSum(int x, int y)
108 {
109 int res = 0;
110 while (top[x] != top[y])
111 {
112 if (deep[x] < deep[y]) swap(x, y);
113 res += query(1, 1, n, id[top[x]], id[x]);
114 x = fa[top[x]];
115 }
116 if (id[x] > id[y]) swap(x, y);
117 return res + query(1, 1, n, id[x], id[y]);
118 }
119
120 void Update(int x, int y, int val)
121 {
122 while (top[x] != top[y])
123 {
124 if (deep[top[x]] < deep[top[y]]) swap(x, y);
125 update(1, 1, n, id[top[x]], id[x], val);
126 x = fa[top[x]];
127 }
128 if (id[x] > id[y]) swap(x, y);
129 update(1, 1, n, id[x], id[y], val);
130 }
131
132 void init()
133 {
134 memset(head, -1, sizeof head);
135 tot = 0, cnt = 0;
136 memset(lazy, 0, sizeof lazy);
137 memset(sum, 0, sizeof sum);
138 memset(son, 0, sizeof son);
139 }
140 };
