# |
제출 시각 |
아이디 |
문제 |
언어 |
결과 |
실행 시간 |
메모리 |
580886 |
2022-06-22T05:15:47 Z |
조영욱(#8362) |
구슬과 끈 (APIO14_beads) |
C++17 |
|
9 ms |
12796 KB |
#include <bits/stdc++.h>
using namespace std;
int n;
typedef pair<int,int> P;
vector<P> adj[200001];
long long dp[200001][2];
vector<P> son[200001];
const long long nn=-2e9-7;
void dfs(int v,int prev) {
for(int i=0;i<adj[v].size();i++) {
P nt=adj[v][i];
if (nt.first!=prev) {
son[v].push_back(nt);
dfs(nt.first,v);
}
}
}
long long ans(int v,int type) {
if (dp[v][type]!=-1) {
return dp[v][type];
}
if (type==0) {
long long mx1=nn;
long long mx2=nn;
long long ret=0;
for(int i=0;i<son[v].size();i++) {
ret+=max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
if (mx1<son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second)) {
mx2=mx1;
mx1=son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
}
else if (mx2<son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second)) {
mx2=son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
}
}
if (mx1+mx2>0) {
ret+=mx1+mx2;
}
return dp[v][type]=ret;
}
long long mx=nn;
long long ret=0;
for(int i=0;i<son[v].size();i++) {
ret+=max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second);
if (mx<son[v][i].second+ans(son[v][i].first,0)-max(ans(son[v][i].first,0),ans(son[v][i].first,1)+son[v][i].second)) {
mx=son[v][i].second;
}
}
return dp[v][type]=ret+mx;
}
int main(void) {
scanf("%d",&n);
for(int i=1;i<n;i++) {
int u,v,w;
scanf("%d %d %d",&u,&v,&w);
adj[u].push_back(P(v,w));
adj[v].push_back(P(u,w));
}
memset(dp,-1,sizeof(dp));
dfs(1,0);
printf("%lld\n",ans(1,0));
}
Compilation message
beads.cpp: In function 'void dfs(int, int)':
beads.cpp:12:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | for(int i=0;i<adj[v].size();i++) {
| ~^~~~~~~~~~~~~~
beads.cpp: In function 'long long int ans(int, int)':
beads.cpp:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
29 | for(int i=0;i<son[v].size();i++) {
| ~^~~~~~~~~~~~~~
beads.cpp:46:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
46 | for(int i=0;i<son[v].size();i++) {
| ~^~~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:56:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
56 | scanf("%d",&n);
| ~~~~~^~~~~~~~~
beads.cpp:59:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
59 | scanf("%d %d %d",&u,&v,&w);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
12756 KB |
Output is correct |
2 |
Correct |
9 ms |
12756 KB |
Output is correct |
3 |
Correct |
8 ms |
12700 KB |
Output is correct |
4 |
Incorrect |
6 ms |
12796 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
12756 KB |
Output is correct |
2 |
Correct |
9 ms |
12756 KB |
Output is correct |
3 |
Correct |
8 ms |
12700 KB |
Output is correct |
4 |
Incorrect |
6 ms |
12796 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
12756 KB |
Output is correct |
2 |
Correct |
9 ms |
12756 KB |
Output is correct |
3 |
Correct |
8 ms |
12700 KB |
Output is correct |
4 |
Incorrect |
6 ms |
12796 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
12756 KB |
Output is correct |
2 |
Correct |
9 ms |
12756 KB |
Output is correct |
3 |
Correct |
8 ms |
12700 KB |
Output is correct |
4 |
Incorrect |
6 ms |
12796 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |