#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int MAXN = 5e5;
const int MAXK = 15;
const int INF = 987654321;
int N, K;
vector<int> adj[MAXN+10];
int par[MAXN+10][30], dep[MAXN+10];
int P[MAXK+10];
void dfs(int now, int bef, int d)
{
par[now][0]=bef;
dep[now]=d;
for(int nxt : adj[now])
{
if(nxt==bef) continue;
dfs(nxt, now, d+1);
}
}
int lca(int u, int v)
{
if(dep[u]>dep[v]) swap(u, v);
for(int i=20; i>=0; i--) if(dep[par[v][i]]>=dep[u]) v=par[v][i];
if(u==v) return u;
for(int i=20; i>=0; i--) if(par[u][i]!=par[v][i]) u=par[u][i], v=par[v][i];
return par[u][0];
}
int dist(int u, int v)
{
int w=lca(u, v);
return dep[u]+dep[v]-dep[w]-dep[w];
}
int half(int u, int v)
{
int w=lca(u, v);
int d=dep[u]+dep[v]-dep[w]-dep[w];
if(d%2) return -1;
d/=2;
if(dep[u]-dep[w]>=d)
{
for(int i=20; i>=0; i--) if(d&(1<<i)) u=par[u][i];
return u;
}
else
{
for(int i=20; i>=0; i--) if(d&(1<<i)) v=par[v][i];
return v;
}
}
int chk[(1<<MAXK)+10], dp[(1<<MAXK)+10], memo[(1<<MAXK)+10];
int main()
{
scanf("%d%d", &N, &K);
for(int i=1; i<N; i++)
{
int u, v;
scanf("%d%d", &u, &v);
adj[u].push_back(v);
adj[v].push_back(u);
}
for(int i=0; i<K; i++)
{
scanf("%d", &P[i]);
}
dfs(1, 1, 1);
for(int i=1; i<=20; i++) for(int j=1; j<=N; j++) par[j][i]=par[par[j][i-1]][i-1];
for(int i=1; i<(1<<K); i++)
{
vector<int> V;
for(int j=0; j<K; j++)
{
if(i&(1<<j)) V.push_back(P[j]);
}
if(V.size()==1)
{
chk[i]=1;
continue;
}
int t=half(V[0], V[1]);
if(t==-1)
{
chk[i]=0;
continue;
}
int d=dist(t, V[0]);
chk[i]=1;
for(int j=0; j<K; j++)
{
if(i&(1<<j))
{
if(d!=dist(P[j], t)) chk[i]=0;
}
else
{
if(d>=dist(P[j], t)) chk[i]=0;
}
}
}
for(int i=0; i<(1<<K); i++)
{
if(i==0) continue;
dp[i]=INF;
for(int j=i; j; j=i&(j-1))
{
if(chk[j])
{
if(dp[i]>dp[i^j]+1)
{
dp[i]=dp[i^j]+1;
memo[i]=i^j;
}
}
}
}
int ans=dp[(1<<K)-1];
if(ans==INF) ans=-1;
printf("%d\n", ans);
if(ans!=-1)
{
int t=(1<<K)-1;
while(t)
{
int x=(t^memo[t]);
//printf("!!%d\n", x);
vector<int> V;
for(int i=0; i<K; i++) if(x&(1<<i)) V.push_back(P[i]);
if(V.size()==1) printf("%d ", V[0]);
else printf("%d ", half(V[0], V[1]));
t=memo[t];
}
}
printf("\n");
}
Compilation message
pastiri.cpp: In function 'int main()':
pastiri.cpp:66:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
66 | scanf("%d%d", &N, &K);
| ~~~~~^~~~~~~~~~~~~~~~
pastiri.cpp:70:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
70 | scanf("%d%d", &u, &v);
| ~~~~~^~~~~~~~~~~~~~~~
pastiri.cpp:76:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
76 | scanf("%d", &P[i]);
| ~~~~~^~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
366 ms |
118508 KB |
Output is correct |
| 2 |
Execution timed out |
1077 ms |
118764 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
145 ms |
13264 KB |
Output is correct |
| 2 |
Correct |
77 ms |
13036 KB |
Output is correct |
| 3 |
Incorrect |
745 ms |
95380 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
17 ms |
12524 KB |
Integer -1 violates the range [1, 2000] |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1081 ms |
95980 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
