Submission #1160465

#	Time	Username	Problem	Language	Result	Execution time	Memory
1160465		JanPham	Museum (CEOI17_museum)	C++20	0 / 100	6 ms	5700 KiB

museum

#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define fi first
#define se second
#define TranLeThanhTam "TranLeThanhTam"
#define all(v) v.begin(),v.end()
#define reset(a,i) memset(a,i,sizeof(a))
#define FOR(i,a,b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i,a,b) for (int i = (a), _b = (b); i >= _b; --i)
#define compact(v) sort(all(v)), v.erase(unique(all(v)), end(v))
#define sz(v) (int) v.size()
#define MASK(i) (1 << (i))

typedef long long ll;
typedef long double lb;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;

const int Thanh_Tam = 2 * 1e5 + 17;
const int inf = 1e9 + 17;
const long long infll = 1e18 + 17;
const int MOD = 1e9 + 7;
const int Log = 18;
const int dx[4] = {-1, 0, 0, 1};
const int dy[4] = {0, -1, 1, 0};
const int max_block_size = 600;
const ll P = 311;
const int maxA = 1e2 + 17;
const int addi = 1e9;
const char dir[4] = {'W', 'S', 'N', 'E'};
const int Mod[3] = {998244353, MOD, 759186269};

ll mul(ll a, ll b, ll mod);
ll binpow(ll a, ll b, ll mod)
{
    ll res = 1;
    while (b > 0)
    {
        if (b & 1) res = mul(res,a,mod);
        b >>= 1;
        a = mul(a,a,mod);
    }
    return res;
}
ll add(ll a, ll b, ll mod = MOD) { return (a + b) % mod;                 }
ll sub(ll a, ll b, ll mod = MOD) { return (a - b + mod) % mod;          }
ll mul(ll a, ll b, ll mod = MOD) { return ((a % mod) * (b % mod)) % mod; }
ll Div(ll a, ll b, ll mod = MOD) { return mul(a, binpow(b, mod - 2, mod), mod); }

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand_range(ll l, ll r) { return uniform_int_distribution<ll>(l,r)(rng); }

int n, k, root, ans = 0;
vector<pii> adj[Thanh_Tam];
int h[Thanh_Tam], child[Thanh_Tam], is_part_of_tree[Thanh_Tam], par[Thanh_Tam];
priority_queue<pii> pq;

void dfs(int u)
{
    is_part_of_tree[u] = true;
    for (pii T : adj[u])
    {
        int v = T.fi, w = T.se;
        if (v == par[u]) continue;
        par[v] = u;
        ++child[u];
        h[v] = h[u] + w;
        dfs(v);
    }

    if (child[u] == 0) pq.push({h[u] - h[par[u]], u});

    return;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

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

    cin >> n >> k >> root;

    FOR(i, 2, n)
    {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].pb({v, w});
        adj[v].pb({u, w});
        ans += w;
    }

    ans <<= 1;
    dfs(root);

    while (n > k)
    {
        int val = pq.top().fi, v = pq.top().se;
        pq.pop();
        ans -= val << 1;
        --child[par[v]];
        if (child[par[v]] == 0 && par[v] != root)
            pq.push({h[par[v]] - h[par[par[v]]], par[v]});
        --n;
    }
    
    int tmp = 0;
    while (!pq.empty())
    {
        tmp = max(tmp, h[pq.top().se]);
        pq.pop();
    }
    cout << ans - tmp;

    return 0;
}

Compilation message (stderr)

museum.cpp: In function 'int main()':
museum.cpp:87:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         freopen(TranLeThanhTam".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
museum.cpp:88:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |         freopen(TranLeThanhTam".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 35
• Subtask 4: 0 / 20