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| #include<stdio.h>
#include<algorithm>
#include<string.h>
#define N 100005
#define inf 0x3f3f3f3f
using namespace std;
struct node
{
int v,next;
} edge[N<<2];
int e[N][3];
int son[N],dep[N],fa[N];
int id,tid[N],top[N],siz[N];
int cnt,pre[N];
int Max[N<<2],Min[N<<2],add[N<<2];
int T,n,a,b,c;
char op[5];
int Scan()
{
int flag = 1,res = 0;
char ch;
while((ch = getchar()) == ' ' || ch == '\n');
if(ch == '-') flag = -1;
else res = ch - '0';
while((ch = getchar()) != ' ' && ch != '\n')
res = res * 10 + ch - '0';
return flag * res;
}
void init()
{
cnt = id = 0;
memset(pre, -1, sizeof(pre));
memset(son, 0, sizeof(son));
memset(siz, 0, sizeof(siz));
memset(Max, -inf, sizeof(Max));
memset(Min, inf, sizeof(Min));
memset(add, 0, sizeof(add));
}
void addEdge(int u, int v)
{
edge[cnt].v = v;
edge[cnt].next = pre[u];
pre[u] = cnt++;
}
void dfs1(int u, int f, int dp)
{
fa[u] = f,dep[u] = dp,son[u] = 0,siz[u] = 1;
for(int i = pre[u]; ~i; i=edge[i].next)
{
int v = edge[i].v;
if(v != f)
{
dfs1(v, u, dp+1);
siz[u] += siz[v];
if(siz[v] > siz[son[u]])
son[u] = v;
}
}
}
void dfs2(int u, int tp)
{
top[u] = tp,tid[u] = ++id;
if(son[u])
dfs2(son[u], tp);
for(int i = pre[u]; ~i; i=edge[i].next)
{
int v = edge[i].v;
if(v != fa[u] && v != son[u])
dfs2(v, v);
}
}
void push_up(int rt)
{
Max[rt] = max(Max[rt<<1], Max[rt<<1|1]);
Min[rt] = min(Min[rt<<1], Min[rt<<1|1]);
}
void push_down(int rt)
{
if(add[rt])
{
add[rt<<1] = (add[rt<<1] + 1) % 2;
add[rt<<1|1] = (add[rt<<1|1] + 1) % 2;
add[rt] = 0;
int maxl = Max[rt<<1],maxr = Max[rt<<1|1];
Max[rt<<1] = -Min[rt<<1];
Min[rt<<1] = -maxl;
Max[rt<<1|1] = -Min[rt<<1|1];
Min[rt<<1|1] = -maxr;
push_up(rt);
}
}
void update_1(int rt, int l, int r, int pos, int v)
{
if(l == r && l == pos)
{
add[rt] = 0;
Max[rt] = Min[rt] = v;
return ;
}
push_down(rt);
int mid = (l + r) >> 1;
if(pos <= mid)
update_1(rt<<1, l, mid, pos, v);
else update_1(rt<<1|1, mid+1, r, pos, v);
push_up(rt);
}
void deal()
{
dfs1(1, 1, 1);
dfs2(1, 1);
for(int i = 1; i < n; ++i)
{
if(dep[e[i][0]] > dep[e[i][1]])
swap(e[i][0], e[i][1]);
update_1(1, 2, n, tid[e[i][1]], e[i][2]);
}
}
void update_2(int rt, int l, int r, int ql, int qr)
{
if(ql <= l && r <= qr)
{
add[rt] = (add[rt] + 1) % 2;
int mmax = Max[rt];
Max[rt] = -Min[rt],Min[rt] = -mmax;
return ;
}
int mid = (l + r) >> 1;
push_down(rt);
if(ql <= mid)
update_2(rt<<1, l, mid, ql, qr);
if(qr > mid)
update_2(rt<<1|1, mid+1, r, ql, qr);
push_up(rt);
}
void lca_up(int u, int v)
{
while(top[u] != top[v])
{
if(dep[top[u]] < dep[top[v]])
swap(u, v);
update_2(1, 2, n, tid[top[u]], tid[u]);
u = fa[top[u]];
}
if(u != v)
{
if(dep[u] > dep[v])
swap(u, v);
update_2(1, 2, n, tid[u]+1, tid[v]);
}
}
int query(int rt, int l, int r, int ql, int qr)
{
if(ql <= l && r <= qr)
return Max[rt];
int mid = (l + r) >> 1;
push_down(rt);
if(qr <= mid)
return query(rt<<1, l, mid, ql, qr);
if(ql > mid)
return query(rt<<1|1, mid+1, r, ql, qr);
return max(query(rt<<1, l, mid, ql, qr), query(rt<<1|1, mid+1, r, ql, qr));
}
int lca_query(int u, int v)
{
int ans = -inf;
while(top[u] != top[v])
{
if(dep[top[u]] < dep[top[v]])
swap(u, v);
ans = max(ans, query(1, 2, n, tid[top[u]], tid[u]));
u = fa[top[u]];
}
if(u != v)
{
if(dep[u] > dep[v])
swap(u, v);
ans = max(ans, query(1, 2, n, tid[u]+1, tid[v]));
}
return ans;
}
int main()
{
T = Scan();
while(T--)
{
init();
n = Scan();
for(int i = 1; i < n; ++i)
{
e[i][0] = Scan(),e[i][1] = Scan(),e[i][2] = Scan();
addEdge(e[i][0], e[i][1]);
addEdge(e[i][1], e[i][0]);
}
deal();
while(~scanf("%s", op) && op[0] != 'D')
{
a = Scan(),b = Scan();
if(op[0] == 'C')
update_1(1, 2, n, tid[e[a][1]], b);
else if(op[0] == 'N')
lca_up(a, b);
else
printf("%d\n", lca_query(a, b));
}
}
return 0;
}
|
