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

#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;
}