bzoj 1036 [LCT version] 分类： templates bzoj 2015-08-06 22:05 20人阅读 评论(0) 收藏

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LCT。单个操作时间复杂度O(logN)，然而常数巨大。

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#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <string>
#include <map>
#include <vector>
#include <stack>
#include <queue>
#include <utility>
#include <iostream>
#include <algorithm>

template<class Num>void read(Num &x)
{
    char c; int flag = 1;
    while((c = getchar()) < '0' || c > '9')
        if(c == '-') flag *= -1;
    x = c - '0';
    while((c = getchar()) >= '0' && c <= '9')
        x = (x<<3) + (x<<1) + (c-'0');
    x *= flag;
    return;
}
template<class Num>void write(Num x)
{
    if(x < 0) putchar('-'), x = -x;
    static char s[20];int sl = 0;
    while(x) s[sl++] = x%10 + '0',x /= 10;
    if(!sl) {putchar('0');return;}
    while(sl) putchar(s[--sl]);
}

const int maxn = 1e5 + 5, INF = 0x3f3f3f3f;

struct TreeNode
{
    int c[2], fa, rev, max, sum;
}S[maxn];
int n, m, pf[maxn], w[maxn];

#define check(x)  x
namespace Data
{
    void Update(int x)
    {
        S[x].max = std::max(std::max(S[S[x].c[0]].max, S[S[x].c[1]].max), w[x]);
        S[x].sum = S[S[x].c[0]].sum + S[S[x].c[1]].sum + w[x];
    }
    void PushDown(int x)
    {
        if(x && S[x].rev)
        {
            std::swap(S[x].c[0], S[x].c[1]);
            S[S[x].c[0]].rev ^= 1;
            S[S[x].c[1]].rev ^= 1;
            S[x].rev = 0;
        }
    }
    void Rotate(int x)
    {
        int y, z, i, j;

        y = S[x].fa, z = S[y].fa;
        j = (S[z].c[1] == y), PushDown(y);
        i = (S[y].c[1] == x), PushDown(x);

        if(check(z)) S[z].c[j] = x;
        else pf[x] = pf[y], pf[y] = 0;

        if(S[x].c[i^1]) S[S[x].c[i^1]].fa = y;

        S[x].fa = z, S[y].fa = x;
        S[y].c[i] = S[x].c[i^1], S[x].c[i^1] = y;

        Update(y), Update(x); 
    }
    void Splay(int v)
    {
        int g = S[v].fa, h = S[g].fa;

        PushDown(v);

        while(check(g))
        {
            if(check(h)) 
            {
                if((S[h].c[1] == g)^(S[g].c[1] == v))
                    Rotate(v);
                else
                    Rotate(g);          
            }
            Rotate(v), g = S[v].fa, h = S[g].fa;    
        }

        Update(v);
    }
}
namespace LCT
{
    void Access(int v)
    {
        int u = v, e = v;
        v = 0;

        while(u)
        {
            Data::Splay(u);

            int &t = S[u].c[1];

            if(check(t))
                pf[t] = u, S[t].fa = 0;

            if(check(v))
                pf[v] = 0, S[v].fa = u;

            t = v, Data::Update(u);
            v = u, u = pf[u];
        }

        Data::Splay(e);
    }
    void MakeRoot(int v)
    {
        Access(v);
        S[v].rev ^= 1;
    }
    void Join(int v,int u)
    {
        MakeRoot(v);
        pf[v] = u;
        Access(v);
    }
    int Query(int u,int v)
    {
        MakeRoot(u);
        Access(v);
        return v;
    }
}
#undef check

struct StarEdge
{
    int u, v;
    void scan()
    {
        read(u), read(v);
    }
    void connect()
    {
        LCT::Join(v, u);
    }
}edge[maxn];

void init()
{
    read(n);

    for(int i = 1; i < n; i++) edge[i].scan();
    for(int i = 1; i <= n; i++) read(w[i]);
}
void solve()
{
    char str[10];
    int x, y;

    for(int i = 1; i <= n; i++)
        S[i].max = S[i].sum = w[i];
    S[0].max = -INF;    
    for(int i = 1; i < n; i++)
        edge[i].connect();

    read(m);

    while(m--)
    {
        scanf("%s", str);
        read(x), read(y);
        switch(str[1])
        {
            case 'H': LCT::Access(x), w[x] = y, Data::Update(x);
                    break;
            case 'S': write(S[LCT::Query(x, y)].sum), puts("");
                    break;
            case 'M': write(S[LCT::Query(x, y)].max), puts(""); 
                    break;
        }
    }
}
int main()
{
#ifndef ONLINE_JUDGE    
    freopen("1036.in","r",stdin);
    freopen("1036.out","w",stdout);
#endif

    init();

    solve();

#ifndef ONLINE_JUDGE
    fclose(stdin);
    fclose(stdout);
#endif
    return 0;       
}

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