/*input
17 1 2
1 3
1 4
4 6
6 7
3 8
3 9
3 10
1 13
13 5
13 11
13 12
13 14
14 15
15 16
15 17
14 2
*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define int long long
#define double long double
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define RE(i,n) for (int i = 1; i <= n; i++)
#define RED(i,n) for (int i = n; i > 0; i--)
#define REPS(i,n) for(int i = 1; (i*i) <= n; i++)
#define REP(i,n) for (int i = 0; i < (int)n; i++)
#define FOR(i,a,b) for (int i = a; i < b; i++)
#define REPD(i,n) for (int i = n-1; i >= 0; i--)
#define FORD(i,a,b) for (int i = a; i >= b; i--)
#define all(v) v.begin(),v.end()
#define pii pair<int,int>
#define vi vector<int>
#define vvi vector<vi>
#define print(arr) for (auto it = arr.begin(); it != arr.end(); ++it) cout << *it << " "; cout << endl;
#define debug(x) cout << x << endl;
#define debug2(x,y) cout << x << " " << y << endl;
#define debug3(x,y,z) cout << x << " " << y << " " << z << endl;
typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
const int INF = 1e18+1;
const int MOD = 1e9+7;
const double PI = 3.14159265358979323846264338;
int raise(int a,int n,int m = MOD){
if(n == 0)return 1;
if(n == 1)return a;
int x = 1;
x *= raise(a,n/2,m);
x %= m;
x *= x;
x %= m;
if(n%2)x*= a;
x %= m;
return x;
}
int floor1(int n,int k){
if(n%k == 0 || n >= 0)return n/k;
return (n/k)-1;
}
int ceil1(int n,int k){
return floor1(n+k-1,k);
}
const int N = 1001;
int n,x,y;
set<int> adj[N];
int vis = 0;
int ans = INF;
vector<pii> edges;
int trynow(int u,int p){
vis--;
if(adj[u].size() < 2 and p)return 0;
vector<int> childs;
for(int v:adj[u]){
if(v == p)continue;
childs.pb(trynow(v,u));
}
sort(all(childs));reverse(all(childs));
int res = 0;
REP(i,childs.size()){
res = max(res,1+i+childs[i]);
}
return res;
}
void delpro(){
REP(i,n-1){
int u = edges[i].f;
int v = edges[i].s;
//cout << u << " " << v << endl;
adj[u].erase(v);adj[v].erase(u);
vis = n;
int curans = max(trynow(x,0),trynow(y,0));
if(!vis){
//cout << "here";
ans = min(ans,curans);
}
adj[u].insert(v);adj[v].insert(u);
}
}
void solve(){
cin >> n >> x >> y;
REP(i,n-1){
int a,b;
cin >> a >> b;
adj[a].insert(b);
adj[b].insert(a);
edges.pb({a,b});
}
delpro();
cout << ans;
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//freopen(".in","r",stdin);freopen(".out","w",stdout);
int t = 1;
//cin >> t;
while(t--){
solve();
}
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
131 ms |
504 KB |
Output is correct |
| 2 |
Correct |
124 ms |
504 KB |
Output is correct |
| 3 |
Correct |
145 ms |
504 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
3 ms |
760 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
