#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
struct edge{
int w,to,nxt;
};
edge ed[N<<1];
int cnt,h[N];
void add(int st,int et,int wi){
cnt++;
ed[cnt].to=et;
ed[cnt].w=wi;
ed[cnt].nxt=h[st];
h[st]=cnt;
}
int sum[N][3],dp[N][3][2],n;
void dfs(int x,int fa){
sum[x][0]=0;
dp[x][0][0]=0;
for(int i=h[x];i;i=ed[i].nxt){
int v=ed[i].to;
if(v==fa)continue;
dfs(v,x);
dp[x][2][1]=max({dp[x][2][1]+max(dp[v][1][0]+ed[i].w,dp[v][0][0]),dp[x][1][0]+ed[i].w+max(sum[v][2],dp[v][0][1]),dp[x][1][1]+ed[i].w+dp[v][0][0]});
dp[x][2][0]=max({dp[x][2][0]+max(dp[v][1][0]+ed[i].w,dp[v][0][0]),dp[x][1][0]+ed[i].w+dp[v][0][0]});
dp[x][1][1]=max({dp[x][1][1]+max(dp[v][1][0]+ed[i].w,dp[v][0][0]),dp[x][0][0]+ed[i].w+max(sum[v][2],dp[v][0][1])});
dp[x][1][0]=max({dp[x][1][0]+max(dp[v][1][0]+ed[i].w,dp[v][0][0]),dp[x][0][0]+ed[i].w+dp[v][0][0]});
dp[x][0][1]=max({dp[x][0][1]+max(dp[v][1][0]+ed[i].w,dp[v][0][0]),dp[x][0][0]+max({ed[i].w+dp[v][1][1],sum[v][2],dp[v][0][1]})});
dp[x][0][0]=dp[x][0][0]+max(dp[v][1][0]+ed[i].w,dp[v][0][0]);
}
sum[x][0]=max(dp[x][0][0],dp[x][0][1]);
sum[x][1]=max(dp[x][1][0],dp[x][1][1]);
sum[x][2]=max(dp[x][2][0],dp[x][2][1]);
}
int main(){
scanf("%d",&n);
for(int i=1,x,y,w;i<n;i++){
scanf("%d%d%d",&x,&y,&w);
add(x,y,w);
add(y,x,w);
}
memset(dp,-63,sizeof dp);
memset(sum,-63,sizeof sum);
dfs(1,0);
printf("%d",max(sum[1][0],sum[1][2]));
return 0;
}
Compilation message
beads.cpp: In function 'int main()':
beads.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
36 | scanf("%d",&n);
| ~~~~~^~~~~~~~~
beads.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
38 | scanf("%d%d%d",&x,&y,&w);
| ~~~~~^~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 2 |
Correct |
5 ms |
7252 KB |
Output is correct |
| 3 |
Correct |
4 ms |
7280 KB |
Output is correct |
| 4 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 5 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 6 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 7 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 8 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 9 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 10 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 11 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 12 |
Correct |
3 ms |
7252 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 2 |
Correct |
5 ms |
7252 KB |
Output is correct |
| 3 |
Correct |
4 ms |
7280 KB |
Output is correct |
| 4 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 5 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 6 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 7 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 8 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 9 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 10 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 11 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 12 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 13 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 14 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 15 |
Correct |
4 ms |
7380 KB |
Output is correct |
| 16 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 17 |
Correct |
3 ms |
7284 KB |
Output is correct |
| 18 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 19 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 20 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 21 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 22 |
Correct |
5 ms |
7252 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 2 |
Correct |
5 ms |
7252 KB |
Output is correct |
| 3 |
Correct |
4 ms |
7280 KB |
Output is correct |
| 4 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 5 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 6 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 7 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 8 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 9 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 10 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 11 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 12 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 13 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 14 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 15 |
Correct |
4 ms |
7380 KB |
Output is correct |
| 16 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 17 |
Correct |
3 ms |
7284 KB |
Output is correct |
| 18 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 19 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 20 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 21 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 22 |
Correct |
5 ms |
7252 KB |
Output is correct |
| 23 |
Correct |
5 ms |
7464 KB |
Output is correct |
| 24 |
Correct |
5 ms |
7380 KB |
Output is correct |
| 25 |
Correct |
4 ms |
7380 KB |
Output is correct |
| 26 |
Correct |
6 ms |
7508 KB |
Output is correct |
| 27 |
Correct |
6 ms |
7508 KB |
Output is correct |
| 28 |
Correct |
5 ms |
7636 KB |
Output is correct |
| 29 |
Correct |
6 ms |
7628 KB |
Output is correct |
| 30 |
Correct |
6 ms |
7636 KB |
Output is correct |
| 31 |
Correct |
6 ms |
7892 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 2 |
Correct |
5 ms |
7252 KB |
Output is correct |
| 3 |
Correct |
4 ms |
7280 KB |
Output is correct |
| 4 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 5 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 6 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 7 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 8 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 9 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 10 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 11 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 12 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 13 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 14 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 15 |
Correct |
4 ms |
7380 KB |
Output is correct |
| 16 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 17 |
Correct |
3 ms |
7284 KB |
Output is correct |
| 18 |
Correct |
4 ms |
7252 KB |
Output is correct |
| 19 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 20 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 21 |
Correct |
3 ms |
7252 KB |
Output is correct |
| 22 |
Correct |
5 ms |
7252 KB |
Output is correct |
| 23 |
Correct |
5 ms |
7464 KB |
Output is correct |
| 24 |
Correct |
5 ms |
7380 KB |
Output is correct |
| 25 |
Correct |
4 ms |
7380 KB |
Output is correct |
| 26 |
Correct |
6 ms |
7508 KB |
Output is correct |
| 27 |
Correct |
6 ms |
7508 KB |
Output is correct |
| 28 |
Correct |
5 ms |
7636 KB |
Output is correct |
| 29 |
Correct |
6 ms |
7628 KB |
Output is correct |
| 30 |
Correct |
6 ms |
7636 KB |
Output is correct |
| 31 |
Correct |
6 ms |
7892 KB |
Output is correct |
| 32 |
Correct |
18 ms |
8680 KB |
Output is correct |
| 33 |
Correct |
18 ms |
8660 KB |
Output is correct |
| 34 |
Correct |
19 ms |
8660 KB |
Output is correct |
| 35 |
Correct |
93 ms |
12748 KB |
Output is correct |
| 36 |
Correct |
115 ms |
12876 KB |
Output is correct |
| 37 |
Correct |
88 ms |
12764 KB |
Output is correct |
| 38 |
Correct |
71 ms |
12800 KB |
Output is correct |
| 39 |
Correct |
70 ms |
12804 KB |
Output is correct |
| 40 |
Correct |
75 ms |
12848 KB |
Output is correct |
| 41 |
Correct |
93 ms |
17008 KB |
Output is correct |
