bzoj2157

LCT板子，打个lazy即可

# include <stdio.h>
# include <stdlib.h>
# include <iostream>
# include <algorithm>
# include <string.h>
# include <map>
# define IL inline
# define RG register
# define Fill(a, b) memset(a, b, sizeof(a))
using namespace std;
typedef long long ll;

IL ll Read(){
    RG char c = getchar(); RG ll x = 0, z = 1;
    for(; c < '0' || c > '9'; c = getchar()) z = c == '-' ? -1 : 1;
    for(; c >= '0' && c <= '9'; c = getchar()) x = (x << 1) + (x << 3) + c - '0';
    return x * z;
}

const int MAXN(200010);
int n, S[MAXN], ch[2][MAXN], fa[MAXN], mx[MAXN], mi[MAXN], sum[MAXN], rev[MAXN], w[MAXN], tag[MAXN];

IL bool Son(RG int x){  return ch[1][fa[x]] == x;  }

IL bool Isroot(RG int x){  return ch[0][fa[x]] != x && ch[1][fa[x]] != x;  }

IL void Update(RG int x){
    sum[x] = sum[ch[0][x]] + sum[ch[1][x]] + w[x];
    mx[x] = max(mx[ch[0][x]], mx[ch[1][x]]);
    mi[x] = min(mi[ch[0][x]], mi[ch[1][x]]);
    if(x > n) mx[x] = max(mx[x], w[x]), mi[x] = min(mi[x], w[x]);
}

IL void Down(RG int x){  swap(mi[x], mx[x]); sum[x] = -sum[x]; mi[x] = -mi[x]; mx[x] = -mx[x]; w[x] = -w[x]; tag[x] ^= 1;  }

IL void Pushdown(RG int x){
    if(tag[x]){
        tag[x] = 0;
        if(ch[0][x]) Down(ch[0][x]);
        if(ch[1][x]) Down(ch[1][x]);
    }
    if(rev[x]) rev[x] = 0, rev[ch[0][x]] ^= 1, rev[ch[1][x]] ^= 1, swap(ch[0][x], ch[1][x]);
}

IL void Rot(RG int x){
    RG int y = fa[x], z = fa[y], c = Son(x);
    if(!Isroot(y)) ch[Son(y)][z] = x; fa[x] = z;
    ch[c][y] = ch[!c][x]; fa[ch[c][y]] = y;
    ch[!c][x] = y; fa[y] = x; Update(y);
}

IL void Splay(RG int x){
    RG int top = 0; S[++top] = x;
    for(RG int y = x; !Isroot(y); y = fa[y]) S[++top] = fa[y];
    while(top) Pushdown(S[top--]);
    for(RG int y = fa[x]; !Isroot(x); Rot(x), y = fa[x])
        if(!Isroot(y)) Son(x) ^ Son(y) ? Rot(x) : Rot(y);
    Update(x);
}

IL void Access(RG int x){  for(RG int y = 0; x; y = x, x = fa[x]) Splay(x), ch[1][x] = y, Update(x);  }

IL void Makeroot(RG int x){  Access(x); Splay(x); rev[x] ^= 1;  }

IL int Findroot(RG int x){  Access(x); Splay(x); while(ch[0][x]) x = ch[0][x]; return x;  }

IL void Split(RG int x, RG int y){  Makeroot(x); Access(y); Splay(y);  }

IL void Link(RG int x, RG int y){  Makeroot(x); fa[x] = y;  }

IL void Cut(RG int x, RG int y){  Split(x, y); fa[x] = ch[0][y] = 0;  }

int main(RG int argc, RG char* argv[]){
    n = Read();
    for(RG int i = 0; i <= n; i++) mx[i] = -2e9, mi[i] = 2e9;
    for(RG int i = 1; i < n; i++){
        RG int u = Read() + 1, v = Read() + 1;
        Link(u, n + i); Link(n + i, v);
        sum[n + i] = mx[n + i] = mi[n + i] = w[n + i] = Read();
    }
    RG int Q = Read(), u, v; RG char c[10];
    while(Q--){
        scanf(" %s", c); u = Read(); v = Read();
        if(c[0] == 'C') Splay(n + u), w[n + u] = v, Update(n + u);
        else{
            u++; v++; Split(u, v);
            if(c[0] == 'N') Down(v);
            else if(c[0] == 'S') printf("%d\n", sum[v]);
            else if(c[1] == 'A') printf("%d\n", mx[v]);
            else printf("%d\n", mi[v]);
        }
    }
    return 0;
}