#include <bits/stdc++.h>
using namespace std;
#define ll int
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("popcnt,sse4,avx2")
const int mxn = 1e5+10;
int N,Q;
vector<int> tree[mxn];
vector<pair<pii,int>> req[mxn];
namespace HLD{
int idx[mxn],link_top[mxn],par[mxn],dep[mxn],bs[mxn],sz[mxn];
ll bit[mxn];
bitset<mxn> done;
void modify(int p,ll v){
done[p] = true;
bit[p] = bit[p+1]+v;
return;
/*
for(;p<mxn;p+=p&-p)bit[p] += v;
return;
*/
}
ll getval(int s,int e){
if(!done[s])return bit[s+1]-bit[e+1];
return bit[s]-bit[e+1];
/*
int re = 0;
for(;e>0;e-= e&-e)re += bit[e];
s--;
for(;s>0;s-= s&-s)re -= bit[s];
return re;
*/
}
int cnt = 0;
void dfs1(int now){
sz[now] = 1;
for(auto nxt:tree[now]){
if(nxt == par[now])continue;
par[nxt] = now;
dep[nxt] = dep[now]+1;
dfs1(nxt);
sz[now] += sz[nxt];
if(!bs[now]||sz[bs[now]]<sz[nxt])bs[now] = nxt;
}
return;
}
void dfs2(int now,int top){
idx[now] = ++cnt;
link_top[now] = top;
if(bs[now])dfs2(bs[now],top);
for(auto nxt:tree[now]){
if(nxt == par[now]||nxt == bs[now])continue;
dfs2(nxt,nxt);
}
return;
}
int LCA1(int a,int b){
int ta = link_top[a],tb = link_top[b];
while(ta != tb){
if(dep[ta]<dep[tb]){
swap(a,b);
swap(ta,tb);
}
a = par[ta];ta = link_top[a];
}
return (idx[a]<idx[b]?a:b);
}
int LCA(int a,int b){
int re = 0;
int ta = link_top[a],tb = link_top[b];
while(ta != tb){
if(dep[ta]<dep[tb]){
swap(a,b);
swap(ta,tb);
}
re += getval(idx[ta],idx[a]);
a = par[ta];ta = link_top[a];
}
if(idx[a]>idx[b])swap(a,b);
re += getval(idx[a],idx[b]);
return re;
}
}
namespace CALC{
ll ans = 0;
ll sum[mxn],dp[mxn];
void dfs(int now){
sort(tree[now].begin(),tree[now].end(),[](int a,int b){return HLD::idx[a]>HLD::idx[b];});
for(auto nxt:tree[now]){
if(nxt == HLD::par[now])continue;
dfs(nxt);
sum[now] += dp[nxt];
}
dp[now] = max(dp[now],sum[now]);
for(auto &i:req[now]){
auto [a,b] = i.fs;
int w = i.sc;
ll ts = sum[now]+HLD::LCA(a,b)+w;
dp[now] = max(dp[now],ts);
}
HLD::modify(HLD::idx[now],sum[now]-dp[now]);
}
void GO(){
dfs(1);
cout<<dp[1]<<'\n';
return;
}
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N;
for(int i = 1;i<N;i++){
int a,b;
cin>>a>>b;
tree[a].push_back(b);
tree[b].push_back(a);
}
int rt = (N+1)>>1;
HLD::dfs1(rt);
HLD::dfs2(rt,rt);
cin>>Q;
while(Q--){
int a,b,c;
cin>>a>>b>>c;
int h = HLD::LCA1(a,b);
req[h].push_back(make_pair(pii(a,b),c));
}
CALC::GO();
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
8280 KB |
Output is correct |
| 2 |
Correct |
2 ms |
8284 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
8284 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
8280 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
8280 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
8280 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
8280 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
60 ms |
15760 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
8280 KB |
Output is correct |
| 2 |
Correct |
2 ms |
8284 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
8284 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
8280 KB |
Output is correct |
| 2 |
Correct |
2 ms |
8284 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
8284 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
