HDU5957 Query on a graph（拓扑找环，BFS序，线段树更新，分类讨论）

#include <map>
#include <set>
#include <cmath>
#include <ctime>
#include <stack>
#include <queue>
#include <cstdio>
#include <cctype>
#include <bitset>
#include <string>
#include <vector>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <functional>
#define PI acos(-1)
#define eps 1e-8
#define fuck(x) cout<<#x<<" = "<<x<<endl;
#define FIN freopen("input.txt","r",stdin);
#define FOUT freopen("output.txt","w+",stdout);
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
//#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
typedef long long LL;
typedef pair<int, int> PII;
const int maxn = 2e5 + 5;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
LL gcd(LL a, LL b) {return b ? gcd(b, a % b) : a;}
LL lcm(LL a, LL b) {return a / gcd(a, b) * b;}
LL powmod(LL a, LL b, LL MOD) {LL ans = 1; while (b) {if (b % 2)ans = ans * a % MOD; a = a * a % MOD; b /= 2;} return ans;}
double dpow(double a, LL b) {double ans = 1.0; while (b) {if (b % 2)ans = ans * a; a = a * a; b /= 2;} return ans;}
int n, q;
struct node {
    int v, nxt, w;
} edge[maxn];
int head[maxn];
int tot;
void add_edge(int u, int v) {
    edge[tot].v = v;
    edge[tot].nxt = head[u];
    head[u] = tot++;
}

int in[maxn];

void top() {
    queue<int>q;
    for (int i = 1; i <= n; i++) if (in[i] == 1) q.push(i);
    while (!q.empty()) {
        int u = q.front(); q.pop();
        for (int i = head[u]; ~i; i = edge[i].nxt) {
            int v = edge[i].v;
            if (in[v] > 1) {
                in[v]--;
                if (in[v] == 1) q.push(v);
            }
        }
    }
}

LL sum[maxn << 2], add[maxn << 2];
void build(int l, int r, int rt) {
    sum[rt] = add[rt] = 0;
    if (l == r) return;
    int m = (l + r) >> 1;
    build(lson);
    build(rson);
}
void PushDown(int m, int rt) {
    if (add[rt]) {
        add[rt << 1] += add[rt];
        add[rt << 1 | 1] += add[rt];
        sum[rt << 1] += add[rt] * (m - (m >> 1));
        sum[rt << 1 | 1] += add[rt] * (m >> 1);
        add[rt] = 0;
    }
}
void PushUP(int rt) {
    sum[rt] = sum[rt << 1] + sum[rt << 1 | 1];
}
void update(int L, int R, int c, int l, int r, int rt) {
    if (L == 0 || R == 0) return;
    if (L <= l && R >= r) {
        sum[rt] += (LL)(r - l + 1) * c;
        add[rt] += c;
        return;
    }
    PushDown(r - l + 1, rt);
    int m = (l + r) >> 1;
    if (L <= m) update(L, R, c, lson);
    if (R > m) update(L, R, c, rson);
    PushUP(rt);
}
LL query(int L, int R, int l, int r, int rt) {
    if (L == 0 || R == 0) return 0;
    if (L <= l && R >= r) return sum[rt];
    PushDown(r - l + 1, rt);
    int m = (l + r) >> 1;
    LL ret = 0;
    if (L <= m) ret += query(L, R, lson);
    if (R > m) ret += query(L, R, rson);
    PushUP(rt);
    return ret;
}
int ver[maxn][2];

int p[maxn], fp[maxn], fa[maxn], sz;
int sonL[maxn], sonR[maxn], ssonL[maxn], ssonR[maxn];
//设val[u]为节点u的权值，fa[u]为父亲,son[u]为儿子,sson[u]孙子
void bfs(int top) { //bfs序找最左和最右的区间
    queue<int>q;
    q.push(top);
    while (!q.empty()) {
        int u = q.front(); q.pop();
        sonL[u] = ssonL[u] = INF;
        sonR[u] = ssonR[u] = 0;
        for (int i = head[u]; i!=-1; i = edge[i].nxt) {
            int v = edge[i].v;
            if (in[v] > 1 || v == fa[u]) continue; //如果连的点在环上就不管
            p[v] = ++sz; //继续打编号
            fp[sz] = v;
            fa[v] = u;
            sonL[u] = min(sonL[u], p[v]);
            sonR[u] = max(sonR[u], p[v]);
            q.push(v);
        }
        ssonL[fa[u]] = min(ssonL[fa[u]], sonL[u]);
        ssonR[fa[u]] = max(ssonR[fa[u]], sonR[u]);
    }
}

void change(int u, int k, int d) {
    int father = fa[u];
    //分类讨论
    //如果k==0，那么就更新单个节点
    //如果k==1，那么就更新u的儿子和爸爸还有自己
    //1)需要讨论是否在环上，环上的话相当于有两个爸爸
    //如果k==2，那么就更新u的儿子和孙子，u的爸爸和u的爷爷，还有自己
    //1）需要讨论u是否在环上，环上的话，有两个爸爸和两个爷爷都要更新
    //2）需要讨论u的儿子和孙子是否在环上
    if (k == 0) update(p[u], p[u], d, 1, n, 1);
    else if (k == 1) {
        update(sonL[u], sonR[u], d, 1, n, 1);
        update(p[u], p[u], d, 1, n, 1);
        if (in[u] == 1) update(p[fa[u]], p[fa[u]], d, 1, n, 1);
        else {
            update(p[ver[u][0]], p[ver[u][0]], d, 1, n, 1);
            update(p[ver[u][1]], p[ver[u][1]], d, 1, n, 1);
        }
    } else if (k == 2) {
        //update(p[u],p[u],d,1,n,1);
        update(sonL[u], sonR[u], d, 1, n, 1);
        update(ssonL[u], ssonR[u], d, 1, n, 1);
        if (in[u] == 1) {
            update(p[fa[u]], p[fa[u]], d, 1, n, 1);
            update(sonL[fa[u]], sonR[fa[u]], d, 1, n, 1);
            if (in[fa[u]] == 1) {
                update(p[fa[fa[u]]], p[fa[fa[u]]], d, 1, n, 1);
            } else {
                update(p[ver[fa[u]][0]], p[ver[fa[u]][0]], d, 1, n, 1);
                update(p[ver[fa[u]][1]], p[ver[fa[u]][1]], d, 1, n, 1);
            }
        } else {
            update(p[u], p[u], d, 1, n, 1);
            int vv[2];
            int cnt = 0;
            for (int i = 0; i < 2; i++) {
                int v = ver[u][i];
                update(p[v], p[v], d, 1, n, 1);
                update(sonL[v], sonR[v], d, 1, n, 1);
                for (int j = 0; j < 2; j++) {
                    if (ver[v][j] == u || ver[v][j] == ver[u][0] || ver[v][j] == ver[u][1]) continue;
                    if (cnt > 0 && ver[v][j] == vv[cnt - 1]) continue;
                    vv[cnt++] = ver[v][j];

                }
            }
            for (int i = 0; i < cnt; i++) {
                update(p[vv[i]], p[vv[i]], d, 1, n, 1);
            }
        }
    }
}
int get_ans(int u, int k) {
    //分类讨论
    //如果k==0，那么就查询单个节点
    //如果k==1，那么就查询u的儿子和爸爸还有自己
    //1)需要讨论是否在环上，环上的话相当于有两个爸爸
    //如果k==2，那么就查询u的儿子和孙子，u的爸爸和u的爷爷，还有自己
    //1）需要讨论u是否在环上，环上的话，有两个爸爸和两个爷爷都要查询
    //2）需要讨论u的儿子和孙子是否在环上
    int ans = 0;
    if (k == 0) ans += query(p[u], p[u], 1, n, 1);
    else if (k == 1) {
        ans += query(sonL[u], sonR[u], 1, n, 1);
        ans += query(p[u], p[u], 1, n, 1);
        if (in[u] == 1) ans += query(p[fa[u]], p[fa[u]], 1, n, 1);
        else {
            ans += query(p[ver[u][0]], p[ver[u][0]], 1, n, 1);
            ans += query(p[ver[u][1]], p[ver[u][1]], 1, n, 1);
        }
    } else if (k == 2) {
        //update(p[u],p[u],d,1,n,1);
        ans += query(sonL[u], sonR[u],  1, n, 1);
        ans += query(ssonL[u], ssonR[u],  1, n, 1);
        if (in[u] == 1) {
            ans += query(p[fa[u]], p[fa[u]], 1, n, 1);
            ans += query(sonL[fa[u]], sonR[fa[u]], 1, n, 1);
            if (in[fa[u]] == 1) {
                ans += query(p[fa[fa[u]]], p[fa[fa[u]]], 1, n, 1);
            } else {
                ans += query(p[ver[fa[u]][0]], p[ver[fa[u]][0]], 1, n, 1);
                ans += query(p[ver[fa[u]][1]], p[ver[fa[u]][1]], 1, n, 1);
            }
        } else {
            ans += query(p[u], p[u], 1, n, 1);
            int vv[2];
            int cnt = 0;
            for (int i = 0; i < 2; i++) {
                int v = ver[u][i];
                ans += query(p[v], p[v], 1, n, 1);
                ans += query(sonL[v], sonR[v], 1, n, 1);
                for (int j = 0; j < 2; j++) {
                    if (ver[v][j] == u || ver[v][j] == ver[u][0] || ver[v][j] == ver[u][1]) continue;
                    if (cnt > 0 && ver[v][j] == vv[cnt - 1]) continue;
                    vv[cnt++] = ver[v][j];
                }
            }
            for (int i = 0; i < cnt; i++) {
                ans += query(p[vv[i]], p[vv[i]], 1, n, 1);
            }
        }
    }
    return ans;
}
int main() {
#ifndef ONLINE_JUDGE
    FIN
#endif
    int T;
    scanf("%d", &T);
    while (T--) {
        scanf("%d", &n);
        for (int i = 1; i <= n; i++) {
            in[i] = 0; fa[i] = 0; head[i] = -1;
        }
        tot = 0;
        sz=0;
        int u, v;
        for (int i = 1; i <= n; i++) {
            scanf("%d%d", &u, &v);
            in[v]++;
            in[u]++;
            add_edge(u, v);
            add_edge(v, u);
        }
        top();
        for (int u = 1; u <= n; u++) {//遍历每一个节点
            if (in[u] > 1) {//如果节点的入度大于1
                int j = 0;
                for (int i = head[u]; i!=-1; i = edge[i].nxt) { //这个节点所有的子树
                    int v = edge[i].v;
                    if (in[v] > 1) {//如果这个点在环上
                        ver[u][j++] = v;//记录点u在环上连的是哪两个点
                    }
                }
                p[u] = ++sz;//给点u编号
                fp[sz] = u;
                bfs(u);
            }
        }
        build(1, n, 1);
        char op[10];
        int k, d;
        scanf("%d", &q);
        while (q--) {
            scanf("%s", op);
            if (op[0] == ‘M‘) {
                scanf("%d%d%d", &u, &k, &d);
                change(u, k, d);
            } else {
                scanf("%d%d", &u, &k);
                printf("%d\n", get_ans(u, k));
            }
        }
    }
}