// Cao Quang Hung
#include <cassert>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
using namespace std;
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define pii pair<int,int>
#define pll pair<long long , long long>
#define vi vector<int>
#define vpii vector<pii>
#define SZ(x) ((int)(x.size()))
#define fi first
#define se second
#define IN(x,y) ((y).find((x))!=(y).end())
#define ALL(t) t.begin(),t.end()
#define FOREACH(i,t) for (typeof(t.begin()) i=t.begin(); i!=t.end(); i++)
#define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
#define REPD(i,a,b) for(int (i)=(a); (i)>=(b);--i)
#define FOR(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define dem(x) __builtin_popcount(x)
#define Mask(x) (1LL << (x))
#define BIT(x, i) ((x) >> (i) & 1)
#define ln '\n'
#define io_faster ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
///mt19937 rnd(time(0));
const int INF = 1e9 , mod = 1e9 + 7;
template <class T1, class T2>
inline T1 mul(T1& x, const T2 &k){ return x = (1LL * x * k) % mod; }
template <class T1 , class T2>
inline T1 pw(T1 x, T2 k){T1 res = 1; for (; k ; k >>= 1){ if (k & 1) mul(res, x); mul(x, x); } return res;}
template <class T>
inline bool minimize(T &x, const T &y){ if (x > y){x = y; return 1;} return 0; }
template <class T>
inline bool maximize(T &x, const T &y){ if (x < y){x = y; return 1;} return 0; }
template <class T>
inline void add(T &x , const T &y){ if ((x += y) >= mod) x -= mod; }
template <class T>
inline T product (const T &x , const T &y) { return 1LL * x * y % mod; }
#define PROB "a"
void file(){
if(fopen(PROB".inp", "r")){
freopen(PROB".inp","r",stdin);
freopen(PROB".out","w",stdout);
}
}
void sinh_(){
// srand(time(0));
// freopen(PROB".inp" , "w" , stdout);
// int n;
}
typedef long long ll;
typedef double db;
const int N = 1e4 + 5;
int n, k, x;
vpii adj[N];
void readip(){
cin >> n >> k >> x;
REP(i, 2, n) {
int u, v, w; cin >> u >> v >> w;
adj[u].eb(v, w);
adj[v].eb(u, w);
}
}
namespace sub3 {
ll dp[N][102][2] = {}, g[102][2];
int sz[N];
void dfs_tree(int u, int p) {
sz[u] = 0;
dp[u][0][0] = dp[u][0][1] = 0;
for (const auto &[v, w] : adj[u]) if (v != p) {
dfs_tree(v, u);
REP(i, 0, min(k, sz[u] + sz[v])) FOR(t, 2) g[i][t] = 1e18;
for (int ku = 0; ku <= min(k, sz[u]); ku++) for (int kv = 0; kv <= min(sz[v], k - ku); ++kv) {
minimize(g[ku + kv][0], dp[u][ku][0] + dp[v][kv][0] + 2 * w);
minimize(g[ku + kv][1], min(dp[u][ku][0] + dp[v][kv][1] + w, dp[u][ku][1] + dp[v][kv][0] + 2 * w));
}
sz[u] += sz[v];
for (int i = 0; i <= min(k, sz[u]); ++i) FOR(t, 2)
minimize(dp[u][i][t] , g[i][t]);
}
sz[u]++;
for (int i = sz[u]; i > 0; --i) {
dp[u][i][0] = dp[u][i - 1][0];
dp[u][i][1] = dp[u][i - 1][1];
}
dp[u][0][0] = dp[u][0][1] = 0;
}
void solve() {
memset(dp, 0x3f, sizeof dp);
dfs_tree(x, -1);
cout << min(dp[x][k][1], dp[x][k][0]) << ln;
}
};
void solve(){
if (k <= 100) {
sub3::solve();
return;
}
}
int main(){
sinh_();
io_faster
file();
int t = 1;
// cin >> t;
while (t--){
readip();
solve();
}
}
Compilation message
museum.cpp: In function 'void readip()':
museum.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
| ^
museum.cpp:144:5: note: in expansion of macro 'REP'
144 | REP(i, 2, n) {
| ^~~
museum.cpp: In function 'void sub3::dfs_tree(int, int)':
museum.cpp:159:26: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
159 | for (const auto &[v, w] : adj[u]) if (v != p) {
| ^
museum.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
| ^
museum.cpp:162:13: note: in expansion of macro 'REP'
162 | REP(i, 0, min(k, sz[u] + sz[v])) FOR(t, 2) g[i][t] = 1e18;
| ^~~
museum.cpp:94:28: warning: unnecessary parentheses in declaration of 't' [-Wparentheses]
94 | #define FOR(i, n) for (int (i) = 0; (i) < (n); ++(i))
| ^
museum.cpp:162:46: note: in expansion of macro 'FOR'
162 | REP(i, 0, min(k, sz[u] + sz[v])) FOR(t, 2) g[i][t] = 1e18;
| ^~~
museum.cpp:94:28: warning: unnecessary parentheses in declaration of 't' [-Wparentheses]
94 | #define FOR(i, n) for (int (i) = 0; (i) < (n); ++(i))
| ^
museum.cpp:171:54: note: in expansion of macro 'FOR'
171 | for (int i = 0; i <= min(k, sz[u]); ++i) FOR(t, 2)
| ^~~
museum.cpp: In function 'void file()':
museum.cpp:125:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
125 | freopen(PROB".inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
museum.cpp:126:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
126 | freopen(PROB".out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 2 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 3 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 4 |
Correct |
3 ms |
16468 KB |
Output is correct |
| 5 |
Correct |
3 ms |
16476 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
9 ms |
17240 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
16988 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
9 ms |
17240 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
16988 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 2 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 3 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 4 |
Correct |
3 ms |
16468 KB |
Output is correct |
| 5 |
Correct |
3 ms |
16476 KB |
Output is correct |
| 6 |
Correct |
9 ms |
17240 KB |
Output is correct |
| 7 |
Incorrect |
9 ms |
16988 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
