#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
const int mxn = 2e5+10;
vector<pii> tree[mxn];
int dp[mxn][2];
int N;
int ans = 0;
vector<pii> v[mxn];
void dfs(int now,int par){
dp[now][0] = 0;
dp[now][1] = -1e9;
for(auto [nxt,w]:tree[now]){
if(nxt == par)continue;
dfs(nxt,now);
dp[now][0] += max(dp[nxt][0],dp[nxt][1]+w);
v[now].push_back(pii(dp[nxt][0]+w-max(dp[nxt][0],dp[nxt][1]+w),nxt));
}
sort(v[now].rbegin(),v[now].rend());
if(!v[now].empty())dp[now][1] = dp[now][0]+v[now][0].fs;
return;
}
void dfs2(int now,int par){
ans = max(ans,dp[now][0]);
sort(v[now].rbegin(),v[now].rend());
for(auto [nxt,w]:tree[now]){
if(nxt == par)continue;
int dp0 = dp[now][0]-max(dp[nxt][0],dp[nxt][1]+w);
int dp1 = -1e9;
if(v[now][0].sc != nxt)dp1 = dp0+v[now][0].fs;
else if(v[now].size()>1)dp1 = dp0+v[now][1].fs;
dp[nxt][0] += max(dp0,dp1+w);
v[nxt].push_back(pii(dp0+w-max(dp0,dp1+w),now));
dfs2(nxt,now);
}
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,c;
cin>>a>>b>>c;
tree[a].push_back(pii(b,c));
tree[b].push_back(pii(a,c));
}
dfs(1,1);
dfs2(1,1);
cout<<ans<<'\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
11356 KB |
Output is correct |
2 |
Correct |
3 ms |
11356 KB |
Output is correct |
3 |
Correct |
3 ms |
11356 KB |
Output is correct |
4 |
Correct |
3 ms |
11420 KB |
Output is correct |
5 |
Correct |
3 ms |
11352 KB |
Output is correct |
6 |
Correct |
3 ms |
11356 KB |
Output is correct |
7 |
Correct |
2 ms |
11356 KB |
Output is correct |
8 |
Correct |
2 ms |
11356 KB |
Output is correct |
9 |
Correct |
3 ms |
11352 KB |
Output is correct |
10 |
Correct |
2 ms |
11352 KB |
Output is correct |
11 |
Correct |
3 ms |
11356 KB |
Output is correct |
12 |
Correct |
3 ms |
11356 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
11356 KB |
Output is correct |
2 |
Correct |
3 ms |
11356 KB |
Output is correct |
3 |
Correct |
3 ms |
11356 KB |
Output is correct |
4 |
Correct |
3 ms |
11420 KB |
Output is correct |
5 |
Correct |
3 ms |
11352 KB |
Output is correct |
6 |
Correct |
3 ms |
11356 KB |
Output is correct |
7 |
Correct |
2 ms |
11356 KB |
Output is correct |
8 |
Correct |
2 ms |
11356 KB |
Output is correct |
9 |
Correct |
3 ms |
11352 KB |
Output is correct |
10 |
Correct |
2 ms |
11352 KB |
Output is correct |
11 |
Correct |
3 ms |
11356 KB |
Output is correct |
12 |
Correct |
3 ms |
11356 KB |
Output is correct |
13 |
Correct |
3 ms |
11352 KB |
Output is correct |
14 |
Correct |
3 ms |
11356 KB |
Output is correct |
15 |
Correct |
3 ms |
11356 KB |
Output is correct |
16 |
Correct |
3 ms |
11356 KB |
Output is correct |
17 |
Correct |
2 ms |
11356 KB |
Output is correct |
18 |
Correct |
3 ms |
11404 KB |
Output is correct |
19 |
Correct |
2 ms |
11356 KB |
Output is correct |
20 |
Correct |
2 ms |
11316 KB |
Output is correct |
21 |
Correct |
2 ms |
11356 KB |
Output is correct |
22 |
Correct |
2 ms |
11356 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
11356 KB |
Output is correct |
2 |
Correct |
3 ms |
11356 KB |
Output is correct |
3 |
Correct |
3 ms |
11356 KB |
Output is correct |
4 |
Correct |
3 ms |
11420 KB |
Output is correct |
5 |
Correct |
3 ms |
11352 KB |
Output is correct |
6 |
Correct |
3 ms |
11356 KB |
Output is correct |
7 |
Correct |
2 ms |
11356 KB |
Output is correct |
8 |
Correct |
2 ms |
11356 KB |
Output is correct |
9 |
Correct |
3 ms |
11352 KB |
Output is correct |
10 |
Correct |
2 ms |
11352 KB |
Output is correct |
11 |
Correct |
3 ms |
11356 KB |
Output is correct |
12 |
Correct |
3 ms |
11356 KB |
Output is correct |
13 |
Correct |
3 ms |
11352 KB |
Output is correct |
14 |
Correct |
3 ms |
11356 KB |
Output is correct |
15 |
Correct |
3 ms |
11356 KB |
Output is correct |
16 |
Correct |
3 ms |
11356 KB |
Output is correct |
17 |
Correct |
2 ms |
11356 KB |
Output is correct |
18 |
Correct |
3 ms |
11404 KB |
Output is correct |
19 |
Correct |
2 ms |
11356 KB |
Output is correct |
20 |
Correct |
2 ms |
11316 KB |
Output is correct |
21 |
Correct |
2 ms |
11356 KB |
Output is correct |
22 |
Correct |
2 ms |
11356 KB |
Output is correct |
23 |
Correct |
5 ms |
11608 KB |
Output is correct |
24 |
Correct |
5 ms |
11608 KB |
Output is correct |
25 |
Correct |
4 ms |
11612 KB |
Output is correct |
26 |
Correct |
7 ms |
12124 KB |
Output is correct |
27 |
Correct |
7 ms |
12124 KB |
Output is correct |
28 |
Correct |
6 ms |
12124 KB |
Output is correct |
29 |
Correct |
7 ms |
12360 KB |
Output is correct |
30 |
Correct |
7 ms |
12272 KB |
Output is correct |
31 |
Correct |
7 ms |
12632 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
11356 KB |
Output is correct |
2 |
Correct |
3 ms |
11356 KB |
Output is correct |
3 |
Correct |
3 ms |
11356 KB |
Output is correct |
4 |
Correct |
3 ms |
11420 KB |
Output is correct |
5 |
Correct |
3 ms |
11352 KB |
Output is correct |
6 |
Correct |
3 ms |
11356 KB |
Output is correct |
7 |
Correct |
2 ms |
11356 KB |
Output is correct |
8 |
Correct |
2 ms |
11356 KB |
Output is correct |
9 |
Correct |
3 ms |
11352 KB |
Output is correct |
10 |
Correct |
2 ms |
11352 KB |
Output is correct |
11 |
Correct |
3 ms |
11356 KB |
Output is correct |
12 |
Correct |
3 ms |
11356 KB |
Output is correct |
13 |
Correct |
3 ms |
11352 KB |
Output is correct |
14 |
Correct |
3 ms |
11356 KB |
Output is correct |
15 |
Correct |
3 ms |
11356 KB |
Output is correct |
16 |
Correct |
3 ms |
11356 KB |
Output is correct |
17 |
Correct |
2 ms |
11356 KB |
Output is correct |
18 |
Correct |
3 ms |
11404 KB |
Output is correct |
19 |
Correct |
2 ms |
11356 KB |
Output is correct |
20 |
Correct |
2 ms |
11316 KB |
Output is correct |
21 |
Correct |
2 ms |
11356 KB |
Output is correct |
22 |
Correct |
2 ms |
11356 KB |
Output is correct |
23 |
Correct |
5 ms |
11608 KB |
Output is correct |
24 |
Correct |
5 ms |
11608 KB |
Output is correct |
25 |
Correct |
4 ms |
11612 KB |
Output is correct |
26 |
Correct |
7 ms |
12124 KB |
Output is correct |
27 |
Correct |
7 ms |
12124 KB |
Output is correct |
28 |
Correct |
6 ms |
12124 KB |
Output is correct |
29 |
Correct |
7 ms |
12360 KB |
Output is correct |
30 |
Correct |
7 ms |
12272 KB |
Output is correct |
31 |
Correct |
7 ms |
12632 KB |
Output is correct |
32 |
Correct |
31 ms |
15700 KB |
Output is correct |
33 |
Correct |
26 ms |
16068 KB |
Output is correct |
34 |
Correct |
28 ms |
15696 KB |
Output is correct |
35 |
Correct |
181 ms |
29680 KB |
Output is correct |
36 |
Correct |
217 ms |
29636 KB |
Output is correct |
37 |
Correct |
152 ms |
29780 KB |
Output is correct |
38 |
Correct |
124 ms |
30428 KB |
Output is correct |
39 |
Correct |
131 ms |
30696 KB |
Output is correct |
40 |
Correct |
121 ms |
30336 KB |
Output is correct |
41 |
Correct |
211 ms |
34752 KB |
Output is correct |