/* * @Author: MaxPhast * @File: test.cpp * @Date: 2026-02-08 21:17:59 */ #include <bits/stdc++.h> using namespace std; #define ii pair <int , int> #define iii pair <int , ii> #define iiii pair <ii , ii> #define FOR(i , l , r) for(int i = (l) , _r = (r) ; i <= _r ; ++ i) #define FORD(i , r , l) for(int i = (r) , _l = (l) ; i >= _l ; -- i) #define ALL(vec) vec.begin() , vec.end() #define UNI(vec) sort(ALL(vec)) , vec.erase(unique(ALL(vec)) , vec.end()) #define pb push_back #define MASK(i) (1ll << i) #define BIT(mask , i) ((mask >> i) & 1ll) #define ON(mask , i) (mask | MASK(i)) #define OFF(mask , i) (mask & (~MASK(i))) #define TURN(mask , i) (mask ^ MASK(i)) #define BP(mask) __builtin_popcountll(mask) #define sqr(x) (1ll * (x) * (x)) #define fi first #define se second #define oo 1e9 #define time() cerr << " \n " << "Time elapsed : " << 1000.0 * clock() / CLOCKS_PER_SEC << "ms." #define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);} template <class X , class Y> bool maxz(X &a , const Y b) { if(a < b) { a = b; return true; } return false; } template <class X , class Y> bool minz(X &a , const Y b) { if(a > b) { a = b; return true; } return false; } namespace MaxPhast { const int N = 1e4 + 5; int n , k , x; int dp[N][N][2]; vector <ii> g[N]; int dfs(int u , int pre) { int sz = 1; FOR(j , 0 , 1) dp[u][1][j] = 0; for(ii &v : g[u]) if(v.fi != pre) { int sz_sub = dfs(v.fi , u); FORD(su , sz , 1) { FOR(sv , 1 , sz_sub) { int s = su + sv; minz(dp[u][s][0] , dp[u][su][0] + dp[v.fi][sv][0] + 2 * v.se); minz(dp[u][s][1] , dp[u][su][0] + dp[v.fi][sv][1] + v.se); minz(dp[u][s][1] , dp[u][su][1] + dp[v.fi][sv][0] + 2 * v.se); } } sz += sz_sub; } return sz; } void solve() { cin >> n >> k >> x; FOR(i , 1 , n - 1) { int u , v , w; cin >> u >> v >> w; g[u].pb(ii(v , w)); g[v].pb(ii(u , w)); } FOR(u , 1 , n) FOR(s , 1 , k) FOR(j , 0 , 1) dp[u][s][j] = oo; dfs(x , -1); cout << min(dp[x][k][0] , dp[x][k][1]); } } signed main() { ios_base :: sync_with_stdio(false) ; cin.tie(nullptr) ; cout.tie(nullptr) ; IO(test); MaxPhast :: solve(); time(); } /* */

museum.cpp: In function 'int main()':
museum.cpp:28:54: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 | #define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);}
      |                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
museum.cpp:110:5: note: in expansion of macro 'IO'
  110 |     IO(test);
      |     ^~
museum.cpp:28:90: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 | #define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);}
      |                                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
museum.cpp:110:5: note: in expansion of macro 'IO'
  110 |     IO(test);
      |     ^~