oj.uz

답안 #862093

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
862093 2023-10-17T14:03:16 Z sleepntsheep Museum (CEOI17_museum) C++17
0 / 100
 153 ms 314196 KB 
#include <cstdio>
#include <cstring>
#include <cassert>
#include <string>
#include <deque>
#include <vector>
#include <map>
#include <queue>
#include <algorithm>
#include <iostream>
#include <utility>
using namespace std;
using ll = long long;
using ld = long double;
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false)

#define N 10002
#define ALL(x) x.begin(), x.end()

int dp[N][N][2];

int n, k, x, sz[N];
vector<pair<int, int>> g[N];

/*
 * at, take, comebacktonode
 *
 * dp[u][j][1] = min (t1 + t2 + ... + td == j - 1) 
 *              ( 2w + dp[v][j][1] )
 * dp[u][j][0] = min (t1 + t2 + ... + td == j - 1)
 *              (dp[v1][t1][1]+2*w1 + ... + dp[vd-1][td-1][1]+2*wd-1) + dp[vd][td][0] + wd
 * 
 * ans = dp[x][k][0]
 */

void dfs(int u, int p)
{
    sz[u] = 1;
    for (auto [w, v] : g[u])
    {
        if (v == p) continue;
        dfs(v, u);
        for (int i = sz[u]; i >= 0; --i) for (int j = sz[v]; j >= 1; --j)
        {
            dp[u][i+j][1] = min(dp[u][i+j][1], 2*w + dp[v][j][1] + dp[u][i][1]);
            dp[u][i+j][0] = min(dp[u][i+j][0], 2*w + dp[v][j][0] + dp[u][i][1]);
            dp[u][i+j][0] = min(dp[u][i+j][0], w + dp[v][j][0] + dp[u][i][1]);
        }
        sz[u] += sz[v];
    }
}

int main()
{
    ShinLena;
    cin >> n >> k >> x;
    for (int i = 1, u, v, w; i < n; ++i)
        cin >> u >> v >> w, g[u].emplace_back(w, v), g[v].emplace_back(w, u);
    for (int i = 1; i <= n; ++i) for (int j = 2; j <= k; ++j) dp[i][k][0] = dp[i][k][1] = 2e9;
    dfs(x, x);
    cout << dp[x][k][0];

    return 0;
}

Subtask #1
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 2652 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 153 ms 314196 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 153 ms 314196 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 1 ms 2652 KB Output isn't correct
2 Halted 0 ms 0 KB -