// g++ -std=c++14
/*
Today might be the chance to grasp the chance to let your talent bloom.
May be tomorrow, the day after, or next year...
May be even when you are 30. I'm not sure if physique has anything to do with it
but if you think that it will never come, it probably never will.
- Tooru Oikawa.
*/
#include<bits/stdc++.h>
typedef long long ll;
typedef long double lld;
using namespace std;
#define endl "\n"
#define fi first
#define se second
#define MEMS(a,b) memset(a,b,sizeof(a))
#define _ ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define __ freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define all(c) c.begin(),c.end()
#define pii pair<int, int>
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r)
{
uniform_int_distribution<int> uid(l, r);
return uid(rng);
}
#define tr(...) cout<<__FUNCTION__<<' '<<__LINE__<<" = ";trace(#__VA_ARGS__, __VA_ARGS__)
template<typename S, typename T>
ostream& operator<<(ostream& out,pair<S,T> const& p){out<<'('<<p.fi<<", "<<p.se<<')';return out;}
template<typename T>
ostream& operator<<(ostream& out,vector<T> const& v){
ll l=v.size();for(ll i=0;i<l-1;i++)out<<v[i]<<' ';if(l>0)out<<v[l-1];return out;}
template <typename T>
ostream &operator<<(ostream &out, set<T> const &v) {
for (auto i = v.begin(); i != v.end(); i++)
out << (*i) << ' ';
return out;
}
template <typename T>
ostream &operator<<(ostream &out, multiset<T> const &v) {
for (auto i = v.begin(); i != v.end(); i++)
out << (*i) << ' ';
return out;
}
template <typename T, typename V>
ostream &operator<<(ostream &out, map<T, V> const &v) {
for (auto i = v.begin(); i != v.end(); i++)
out << "\n" << (i->first) << ":" << (i->second);
return out;
}
template<typename T>
void trace(const char* name, T&& arg1){cout<<name<<" : "<<arg1<<endl;}
template<typename T, typename... Args>
void trace(const char* names, T&& arg1, Args&&... args){
const char* comma = strchr(names + 1, ',');cout.write(names, comma-names)<<" : "<<arg1<<" | ";trace(comma+1,args...);}
const int N = 1e4 + 2;
vector<vector<pii>> g(N);
int dp[N][N][2]; // 0-> for coming back, 1 -> staying
int n, k, x;
const int inf = 1e9 + 1;
int sub[N];
void dfs(int v, int p) {
sub[v] = 1;
dp[v][1][0] = 0;
dp[v][1][1] = 0;
for (auto u : g[v]) {
if (u.fi == p) continue;
dfs(u.fi, v);
sub[v] += sub[u.fi];
}
int c = 1;
for (auto u : g[v]) {
if (u.fi == p) continue;
c += sub[u.fi];
for (int q = 1; q >= 0; q--) {
if (q == 0) {
for (int j = c; j > 0; j--) {
for (int i = 1; i <= sub[u.fi] && j - i >= 0; i++) {
if (dp[u.fi][i][0] != inf) {
dp[v][j][0] = min(dp[v][j][0], dp[u.fi][i][0] + dp[v][j - i][0] + (u.se * 2));
}
}
}
} else if (q == 1) {
for (int j = c; j > 0; j--) {
for (int i = 0; i <= sub[u.fi] && j - i >= 0; i++) {
if (dp[u.fi][i][0] != inf) {
dp[v][j][1] = min(dp[v][j][1], dp[u.fi][i][1] + dp[v][j - i][0] + u.se);
dp[v][j][1] = min(dp[v][j][1], dp[u.fi][i][0] + dp[v][j - i][1] + (u.se) * 2);
}
}
}
}
}
}
dp[v][0][0] = dp[v][0][1] = 0;
}
int solve() {
for (int i = 0; i < N; i++)
for (int j = 0; j < N; j++)
for (int k = 0; k < 2; k++)
dp[i][j][k] = inf;
cin >> n >> k >> x;
for (int i = 0; i < n - 1; i++) {
int v, u, w;
cin >> v >> u >> w;
g[u].push_back({v, w});
g[v].push_back({u, w});
}
dfs(x, 0);
cout << dp[x][k][1] << endl;
return 0;
}
int32_t main(){ _
int t;
// cin >> t;
t = 1;
while (t--) solve();
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
411 ms |
783736 KB |
Output is correct |
2 |
Correct |
416 ms |
783864 KB |
Output is correct |
3 |
Correct |
408 ms |
783608 KB |
Output is correct |
4 |
Correct |
415 ms |
783744 KB |
Output is correct |
5 |
Correct |
400 ms |
783608 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
3129 ms |
784120 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
3129 ms |
784120 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
411 ms |
783736 KB |
Output is correct |
2 |
Correct |
416 ms |
783864 KB |
Output is correct |
3 |
Correct |
408 ms |
783608 KB |
Output is correct |
4 |
Correct |
415 ms |
783744 KB |
Output is correct |
5 |
Correct |
400 ms |
783608 KB |
Output is correct |
6 |
Execution timed out |
3129 ms |
784120 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |