oj.uz

답안 #780421

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
780421 2023-07-12T08:56:25 Z quochuy147 Museum (CEOI17_museum) C++14
20 / 100
 579 ms 784152 KB 
#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ll long long
#define mp make_pair
#define pb push_back
#define pii pair<int, int>
#define pll pair<ll, ll>
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define file "name" 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b){if (a > b) {a = b; return true;} return false;}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b){if (a < b) {a = b; return true;} return false;}

const int mod = 1e9 + 7;
const int N = 1e4 + 5;
const int inf = 1e9;

int n, k, x;
int sz[N];
int f[N][2][N];
vector <pii> a[N];

void inp()
{
    cin >> n >> k >> x;
    for(int i = 1; i < n; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        a[u].pb({v, w});
        a[v].pb({u, w});
    }
}

void size_subtree(int u, int pre) {
    sz[u] = 1;
    for(auto v : a[u]) {
        if(v.fi == pre) continue;
        size_subtree(v.fi, u);
        sz[u] += sz[v.fi];
    }
}

void dfs(int u, int pre) {
    // f[u][0].assign(sz[u] + 5, inf);
    // f[u][1].assign(sz[u] + 5, inf);
    // f[u][0][0] = f[u][0][1] = f[u][1][0] = f[u][1][1] = 0;
    int tot = 1;
    for(auto e : a[u]) {
        int v = e.fi, w = e.se;
        if(v == pre) continue;
        dfs(v, u);
        tot += sz[v];
        for(int i = tot; i >= 2; --i)
            for(int j = max(0, i - tot + sz[v]); j <= min(i, sz[v]); ++j) {
                minimize(f[u][0][i], f[u][0][i - j] + f[v][1][j] + 2 * w);
                minimize(f[u][0][i], f[u][1][i - j] + f[v][0][j] + w);
                minimize(f[u][1][i], f[u][1][i - j] + f[v][1][j] + 2 * w);
            }
        tot += sz[v];
    }
}

void solve()
{
    for(int i = 1; i <= n; ++i)
        for(int j = 2; j <= n; ++j) f[i][0][j] = f[i][1][j] = inf;
    size_subtree(x, x);
    dfs(x, x);
    cout << f[x][0][k];
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    // freopen(file".inp" , "r" , stdin);
    // freopen(file".out" , "w" , stdout);
    inp();
    solve();
    return 0;
}

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 724 KB Output is correct
2 Correct 1 ms 724 KB Output is correct
3 Correct 1 ms 724 KB Output is correct
4 Correct 1 ms 596 KB Output is correct
5 Correct 1 ms 724 KB Output is correct

Subtask #2
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 579 ms 784152 KB Output is correct
2 Incorrect 535 ms 784152 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 579 ms 784152 KB Output is correct
2 Incorrect 535 ms 784152 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 724 KB Output is correct
2 Correct 1 ms 724 KB Output is correct
3 Correct 1 ms 724 KB Output is correct
4 Correct 1 ms 596 KB Output is correct
5 Correct 1 ms 724 KB Output is correct
6 Correct 579 ms 784152 KB Output is correct
7 Incorrect 535 ms 784152 KB Output isn't correct
8 Halted 0 ms 0 KB -