// 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];
}
for (auto u : g[v]) {
if (u.fi == p) continue;
for (int q = 1; q >= 0; q--) {
if (q == 0) {
for (int j = k; 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 = k; 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();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
403 ms |
783736 KB |
Output is correct |
2 |
Correct |
411 ms |
783608 KB |
Output is correct |
3 |
Correct |
415 ms |
783736 KB |
Output is correct |
4 |
Correct |
410 ms |
783608 KB |
Output is correct |
5 |
Correct |
419 ms |
783736 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
451 ms |
784120 KB |
Output is correct |
2 |
Correct |
468 ms |
784248 KB |
Output is correct |
3 |
Correct |
574 ms |
784504 KB |
Output is correct |
4 |
Correct |
532 ms |
784352 KB |
Output is correct |
5 |
Correct |
515 ms |
784212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
451 ms |
784120 KB |
Output is correct |
2 |
Correct |
468 ms |
784248 KB |
Output is correct |
3 |
Correct |
574 ms |
784504 KB |
Output is correct |
4 |
Correct |
532 ms |
784352 KB |
Output is correct |
5 |
Correct |
515 ms |
784212 KB |
Output is correct |
6 |
Correct |
458 ms |
784128 KB |
Output is correct |
7 |
Correct |
564 ms |
784472 KB |
Output is correct |
8 |
Correct |
421 ms |
784188 KB |
Output is correct |
9 |
Correct |
420 ms |
784120 KB |
Output is correct |
10 |
Correct |
434 ms |
784120 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
403 ms |
783736 KB |
Output is correct |
2 |
Correct |
411 ms |
783608 KB |
Output is correct |
3 |
Correct |
415 ms |
783736 KB |
Output is correct |
4 |
Correct |
410 ms |
783608 KB |
Output is correct |
5 |
Correct |
419 ms |
783736 KB |
Output is correct |
6 |
Correct |
451 ms |
784120 KB |
Output is correct |
7 |
Correct |
468 ms |
784248 KB |
Output is correct |
8 |
Correct |
574 ms |
784504 KB |
Output is correct |
9 |
Correct |
532 ms |
784352 KB |
Output is correct |
10 |
Correct |
515 ms |
784212 KB |
Output is correct |
11 |
Correct |
458 ms |
784128 KB |
Output is correct |
12 |
Correct |
564 ms |
784472 KB |
Output is correct |
13 |
Correct |
421 ms |
784188 KB |
Output is correct |
14 |
Correct |
420 ms |
784120 KB |
Output is correct |
15 |
Correct |
434 ms |
784120 KB |
Output is correct |
16 |
Correct |
1278 ms |
784048 KB |
Output is correct |
17 |
Execution timed out |
3126 ms |
784176 KB |
Time limit exceeded |
18 |
Halted |
0 ms |
0 KB |
- |