#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define Lg(x) 31 - __builtin_clz(x)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 1e4 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void setupIO(){
#define name "Whisper"
//Phu Trong from Nguyen Tat Thanh High School for gifted student
srand(time(NULL));
cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
//freopen(name".inp", "r", stdin);
//freopen(name".out", "w", stdout);
cout << fixed << setprecision(10);
}
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int numNode, staNode, K;
vector<pair<int, int>> G[MAX];
int dp[MAX][MAX][2];
int sz[MAX];
/*
0. start a path at u go to u's subtree and end at u
1. start a path at u go to u's subtree and end at a node in subtree
*/
void dfs(int u, int p = -1){
sz[u] = 1;
for (pair<int, int>& x : G[u]){
int v = x.first, w = x.second;
if(v ^ p){
dfs(v, u);
for (int k = sz[u]; k >= 0; --k){
for (int l = sz[v]; l >= 0; --l){
minimize(dp[u][l + k][0], dp[v][l][0] + dp[u][k][0] + 2 * w);
minimize(dp[u][l + k][1], dp[v][l][1] + dp[u][k][0] + w);
minimize(dp[u][l + k][1], dp[v][l][0] + dp[u][k][0] + w);
}
}
sz[u] += sz[v];
}
}
}
void Whisper(){
cin >> numNode >> K >> staNode;
for (int i = 1; i < numNode; ++i){
int u, v, w; cin >> u >> v >> w;
G[u].emplace_back(v, w);
G[v].emplace_back(u, w);
}
for (int i = 1; i <= numNode; ++i)
for (int j = 2; j <= numNode; ++j)
dp[i][j][0] = dp[i][j][1] = LINF;
dfs(staNode);
cout << min(dp[staNode][K][1], dp[staNode][K][0]);
}
signed main(){
setupIO();
int Test = 1;
// cin >> Test;
for ( int i = 1 ; i <= Test ; i++ ){
Whisper();
if (i < Test) cout << '\n';
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
4700 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
498 ms |
1048576 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
498 ms |
1048576 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
4700 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |