Submission #1126864

#	Time	Username	Problem	Language	Result	Execution time	Memory
1126864		ntdaccode	Museum (CEOI17_museum)	C++20	100 / 100	827 ms	785232 KiB

museum

#include<bits/stdc++.h>
#define fori(i,a,b) for(int i=a;i<=b;i++)
#define pb push_back

using namespace std;

typedef pair<int,int> ii;
typedef tuple<int,int,int> tp;

const int N = 1e4 + 10;

int n, k, root, f[2][N][N], g[2][N];
vector<ii> ke[N];
int sz[N];

void dfs(int u,int p = 0)
{
  sz[u] = 1;
  for(int i = 0;i <= 1; i++) f[i][u][1] = f[i][u][0] = 0;
  for(ii tmp : ke[u]) {
    int v = tmp.first, w = tmp.second;
    if(v == p) continue;
    dfs(v,u);
    for(int i = 0;i <= sz[u] + sz[v]; i++) g[0][i] = g[1][i] =  1e9;
    for(int i = 1;i <= min(k,sz[u]); i++) {
      for(int j = 0;j <= min(k,sz[v]); j++) {
        if(i + j > k) break;
        g[0][i + j] = min(g[0][i + j], f[0][u][i] + f[0][v][j] + 2 * w);
        g[1][i + j] = min(g[1][i + j], f[0][u][i] + f[1][v][j] + w);
        g[1][i + j] = min(g[1][i + j], f[1][u][i] + f[0][v][j] + 2 * w);
      }
    }
    sz[u] += sz[v];
    for(int i = 1;i <= sz[u]; i++){
      for(int j = 0;j <= 1; j++) f[j][u][i] = min(g[j][i], f[j][u][i]);
    }
  }
}

int32_t main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);

  if(fopen("1.inp","r")) {
    freopen("1.inp","r",stdin);
    freopen("1.out","w",stdout);
  }

  #define task ""
  if(fopen(task".inp","r")) {
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);
  }
  cin >> n >> k >> root;
  for(int i = 1;i <= n - 1; i++) {
    int u,v,w;
    cin >> u >> v >> w;
    ke[u].pb({v,w});
    ke[v].pb({u,w});
  }
  for(int i = 1;i <= n; i++) {
    for(int j = 0;j <= n; j++) {
      for(int e = 0;e <= 1; e++) f[e][i][j] = 1e9;
    }
  }
  dfs(root,0);
  cout << f[1][root][k];



}

Compilation message (stderr)

museum.cpp: In function 'int32_t main()':
museum.cpp:47:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     freopen("1.inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~
museum.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen("1.out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~
museum.cpp:53:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
museum.cpp:54:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |     freopen(task".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20