# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1041826 | MMihalev | Beads and wires (APIO14_beads) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<iostream>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<tuple>
#include<set>
#include<map>
#include<random>
#include<chrono>
using namespace std;
const short MAX_N=1e4+4;
const int INF=2e9+1e8;
int dp[MAX_N][2];
short n;
vector<pair<short,short>>g[MAX_N];
void reset()
{
for(short i=1;i<=n;i++)
{
dp[i][0]=0;
dp[i][1]=-INF;
}
}
void dfs(short u,short par)
{
short ch=0,i;
vector<int>suf;
int pref=0;
for(auto [v,edge]:g[u])
{
if(v==par)continue;
ch++;
dfs(v,u);
suf.push_back(max(edge+dp[v][1],dp[v][0]));
}
for(i=ch-2;i>=0;i--)
{
suf[i]+=suf[i+1];
}
i=0;
for(auto [v,edge]:g[u])
{
if(v==par)continue;
dp[u][1]=max(dp[u][1],(i-1>=0 ? pref[i-1] : 0)+(dp[v][0]+edge)+(i+1<ch ? suf[i+1] : 0));
pref+=max(edge+dp[v][1],dp[v][0]);
i++;
}
dp[u][0]=pref;
//vector<int>().swap(pref);vector<int>().swap(suf);
}
signed main ()
{
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin>>n;
for(short i=1;i<n;i++)
{
short u,v,c;
cin>>u>>v>>c;
g[u].push_back({v,c});
g[v].push_back({u,c});
}
int ans=0;
for(short i=1;i<=n;i++)
{
reset();
dfs(i,0);
ans=max(ans,dp[i][0]);
}
cout<<ans<<"\n";
return 0;
}