http://www.lydsy.com/JudgeOnline/problem.php?id=1103

樹剖邊權轉點權，vector存圖卡一下午RE

氣炸。。

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>

using namespace std;
const int N = 250011
 
;

#define yxy getchar()
#define lson jd << 1
#define rson jd << 1 | 1

#define RR freopen("gg.in", "r", stdin)

int top[N], deep[N], fa[N], size[N], son[N], tree[N];
int now = 1, n, Ty, Tim, ans;
vector <int> vec[N << 2];
int W[N << 2];
int head[N];
struct
 
 Node {int u, v, nxt;} G[N << 1];

void add(int u, int v) {
    G[now].v = v; G[now].nxt = head[u]; head[u] = now ++;
}

inline int read() {
    int x = 0; char c = yxy;
    while(c < ‘0‘ || c > ‘9‘) c = yxy;
    while(c >= ‘0‘ && c <= ‘9‘) x = x * 10 + c - ‘0‘, c = yxy;
    
 
return x;
}

void Dfs_son(int u, int f_, int dep) {
    fa[u] = f_;
    deep[u] = dep;
    size[u] = 1;
    for(int i = head[u]; ~ i; i = G[i].nxt) {
        int v = G[i].v;
        if(v != f_) {
            Dfs_son(v, u, dep + 1);
            size[u] += size[v];
            if(size[v] > size[son[u]]) son[u] = v;
        }
    }
}

void Dfs_un(int u, int tp) {
    top[u] = tp;
    tree[u] = ++ Tim;
    if(!son[u]) return ;
    Dfs_un(son[u], tp);
    for(int i = head[u]; ~ i; i = G[i].nxt) {
        int v = G[i].v;
        if(v != fa[u] && v != son[u]) Dfs_un(v, v);
    }
}

void Build_tree(int l, int r, int jd) {
    if(l == r) {
        if(l != 1) W[jd] ++; return ;
    }
    int mid = (l + r) >> 1;
    Build_tree(l, mid, lson);
    Build_tree(mid + 1, r, rson);
    W[jd] = W[lson] + W[rson];
}

void Sec_A(int l, int r, int jd, int x, int y) {
    if(x <= l && r <= y) {
        ans += W[jd];
        return ;
    }
    int mid = (l + r) >> 1;
    if(x <= mid) Sec_A(l, mid, lson, x, y);
    if(y > mid)  Sec_A(mid + 1, r, rson, x, y);
}

inline int Sec_A_imp(int x) {
    int tp1 = top[x], ret(0);
    while(tp1 != 0) {
        ans = 0;
        Sec_A(1, n, 1, tree[tp1], tree[x]);
        ret += ans;
        x = fa[tp1];
        tp1 = top[x];
    }
    return ret;
}

void Poi_G(int l, int r, int jd, int x) {
    if(l == r) {
        W[jd] = 0; return ;
    }
    int mid = (l + r) >> 1;
    if(x <= mid) Poi_G(l, mid, lson, x);
    else Poi_G(mid + 1, r, rson, x);
    W[jd] = W[lson] + W[rson];
}

int main()
{
    n = read();
    for(int i = 1; i <= n; i ++) head[i] = -1;
    for(int i = 1; i < n; i ++) {
        int u = read(), v = read();
        if(u > v) swap(u, v);
        add(u, v);
    }
    Dfs_son(1, 0, 1);
    Dfs_un(1, 1);
    Build_tree(1, n, 1);
    Ty = read(); Ty += (n - 1);
    while(Ty --) {
        char c[15]; scanf("%s", c);
        if(c[0] == ‘W‘) {
            int x = read();
            printf("%d\n", Sec_A_imp(x));
        } else {
            int x = read(), y = read();
            if(x < y) swap(x, y);
            Poi_G(1, n, 1, tree[x]);
        }
    }
    return 0;
}

[POI] 大都市meg