This commit is contained in:
hanyixuanten committed
1 parent
2e796fa148
commit
ed0d5cf6e7
2 files changed
+228
No files matched your search
@@ -0,0 +1,156 @@
|
||||
#include<bits/stdc++.h>
|
||||
using namespace std;
|
||||
int n;
|
||||
vector<pair<int, int>> fri[200005];
|
||||
pair<int, int> edge[200005];
|
||||
int a[200005];
|
||||
int fa[200005];
|
||||
int dfn[200005];
|
||||
int nowdfn;
|
||||
int cnt[200005];
|
||||
int son[200005];
|
||||
int top[200005];
|
||||
int dep[200005];
|
||||
int m;
|
||||
struct SEG{
|
||||
int num[3][800005];
|
||||
bool lt[800005];
|
||||
void pu(int now, int op) {
|
||||
if(op == 0) num[op][now] = num[op][now * 2] + num[op][now * 2 + 1];
|
||||
else if(op == 1) num[op][now] = max(num[op][now * 2], num[op][now * 2 + 1]);
|
||||
else num[op][now] = min(num[op][now * 2], num[op][now * 2 + 1]);
|
||||
}
|
||||
void pu(int now) {pu(now, 0), pu(now, 1), pu(now, 2);}
|
||||
void dorev(int now) {
|
||||
lt[now] ^= 1;
|
||||
num[0][now] = -num[0][now];
|
||||
int tmp = num[1][now];
|
||||
num[1][now] = -num[2][now];
|
||||
num[2][now] = -tmp;
|
||||
}
|
||||
void pd(int now, int nl, int nr) {
|
||||
if(!lt[now]) return;
|
||||
dorev(now * 2);
|
||||
dorev(now * 2 + 1);
|
||||
lt[now] = 0;
|
||||
}
|
||||
void edit(int now, int nl, int nr, int l, int nn) {
|
||||
if(l < nl || l > nr) return;
|
||||
if(nl == nr) {
|
||||
num[0][now] = nn, num[1][now] = nn, num[2][now] = nn;
|
||||
return;
|
||||
}
|
||||
int nmid = (nl + nr) >> 1;
|
||||
pd(now, nl, nr);
|
||||
edit(now * 2, nl, nmid, l, nn);
|
||||
edit(now * 2 + 1, nmid + 1, nr, l, nn);
|
||||
pu(now);
|
||||
}
|
||||
void rev(int now, int nl, int nr, int l, int r) {
|
||||
if(nr < l || nl > r) return;
|
||||
if(l <= nl && nr <= r) {
|
||||
dorev(now);
|
||||
return;
|
||||
}
|
||||
pd(now, nl, nr);
|
||||
int nmid = (nl + nr) >> 1;
|
||||
rev(now * 2, nl, nmid, l, r);
|
||||
rev(now * 2 + 1, nmid + 1, nr, l, r);
|
||||
pu(now);
|
||||
}
|
||||
int query(int now, int nl, int nr, int l, int r, int op) {
|
||||
if(nr < l || nl > r) return (op==2)?INT_MAX:((op==1)?INT_MIN:0);
|
||||
if(l <= nl && nr <= r) {
|
||||
return num[op][now];
|
||||
}
|
||||
int nmid = (nl + nr) >> 1;
|
||||
pd(now, nl, nr);
|
||||
if(op == 0) return query(now * 2, nl, nmid, l, r, op) + query(now * 2 + 1, nmid + 1, nr, l, r, op);
|
||||
else if(op == 1) return max(query(now * 2, nl, nmid, l, r, op), query(now * 2 + 1, nmid + 1, nr, l, r, op));
|
||||
else return min(query(now * 2, nl, nmid, l, r, op), query(now * 2 + 1, nmid + 1, nr, l, r, op));
|
||||
}
|
||||
}seg;
|
||||
void dfs1(int now, int from) {
|
||||
cnt[now] = 1;
|
||||
for(pair<int, int> i : fri[now]) {
|
||||
if(i.second == from) continue;
|
||||
a[i.second] = i.first; // 边权转点权
|
||||
fa[i.second] = now;
|
||||
dep[i.second] = dep[now] + 1;
|
||||
dfs1(i.second, now);
|
||||
cnt[now] += cnt[i.second];
|
||||
if(cnt[i.second] > cnt[son[now]]) son[now] = i.second;
|
||||
}
|
||||
}
|
||||
void dfs2(int now, int from) {
|
||||
dfn[now] = ++nowdfn;
|
||||
seg.edit(1, 1, n, nowdfn, a[now]);
|
||||
top[now] = from;
|
||||
if(son[now]) dfs2(son[now], from);
|
||||
for(pair<int, int> i : fri[now]) {
|
||||
if(i.second == son[now] || i.second == fa[now]) continue;
|
||||
dfs2(i.second, i.second);
|
||||
}
|
||||
}
|
||||
void rev(int u, int v) {
|
||||
while(top[u] != top[v]) {
|
||||
if(dep[top[u]] < dep[top[v]]) swap(u, v);
|
||||
seg.rev(1, 1, n, dfn[top[u]], dfn[u]);
|
||||
u = fa[top[u]];
|
||||
}
|
||||
if(dep[u] < dep[v]) swap(u, v);
|
||||
if(dfn[v] + 1 <= dfn[u])
|
||||
seg.rev(1, 1, n, dfn[v] + 1, dfn[u]);
|
||||
}
|
||||
int f(int u, int v, int op) {
|
||||
int ans = 0;
|
||||
if(op == 1) ans = INT_MIN;
|
||||
if(op == 2) ans = INT_MAX;
|
||||
while(top[u] != top[v]) {
|
||||
if(dep[top[u]] < dep[top[v]]) swap(u, v);
|
||||
if(op == 0) ans += seg.query(1, 1, n, dfn[top[u]], dfn[u], 0);
|
||||
else if(op == 1) ans = max(ans, seg.query(1, 1, n, dfn[top[u]], dfn[u], 1));
|
||||
else ans = min(ans, seg.query(1, 1, n, dfn[top[u]], dfn[u], 2));
|
||||
u = fa[top[u]];
|
||||
}
|
||||
if(dep[u] < dep[v]) swap(u, v);
|
||||
if(dfn[v] + 1 <= dfn[u]) {
|
||||
if(op == 0) ans += seg.query(1, 1, n, dfn[v] + 1, dfn[u], 0);
|
||||
else if(op == 1) ans = max(ans, seg.query(1, 1, n, dfn[v] + 1, dfn[u], 1));
|
||||
else ans = min(ans, seg.query(1, 1, n, dfn[v] + 1, dfn[u], 2));
|
||||
}
|
||||
return ans;
|
||||
}
|
||||
int main() {
|
||||
scanf("%d", &n);
|
||||
for(int i = 1, u, v, w; i < n; ++i) {
|
||||
scanf("%d%d%d", &u, &v, &w);
|
||||
u++, v++;
|
||||
fri[u].push_back({w, v});
|
||||
fri[v].push_back({w, u});
|
||||
edge[i] = {u, v};
|
||||
}
|
||||
dfs1(1, 0);
|
||||
dfs2(1, 1);
|
||||
scanf("%d", &m);
|
||||
while(m--) {
|
||||
char op[5];
|
||||
int u, v;
|
||||
scanf("%s%d%d", op, &u, &v);
|
||||
if(op[0] == 'C') {
|
||||
pair<int, int> ed = edge[u];
|
||||
if(dep[ed.first] > dep[ed.second]) u = ed.first;
|
||||
else u = ed.second;
|
||||
seg.edit(1, 1, n, dfn[u], v);
|
||||
} else if(op[0] == 'N') {
|
||||
rev(u + 1, v + 1);
|
||||
} else if(op[0] == 'S') {
|
||||
printf("%d\n", f(u + 1, v + 1, 0));
|
||||
} else if(op[1] == 'A') {
|
||||
printf("%d\n", f(u + 1, v + 1, 1));
|
||||
} else {
|
||||
printf("%d\n", f(u + 1, v + 1, 2));
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
Reference in new issue
Block a user