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답안 #223912

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
223912 2020-04-16T20:44:24 Z Leonardo_Paes Museum (CEOI17_museum) C++17
100 / 100
 1089 ms 169980 KB 
#include <bits/stdc++.h>

using namespace std;

#define f first
#define s second

#pragma "Ofast"

const int maxn = 1e4+10, inf = 0x3f3f3f3f;

typedef pair<int,int> pii;

int n, k, x, siz[maxn], dp[maxn][maxn][2];

vector<pii> grafo[maxn];

inline void dfs(const int &u, const int &p = 0){
    siz[u] = 1;

    for(auto v : grafo[u]){
        if(v.f == p) continue;

        dfs(v.f, u);

        siz[u] += siz[v.f];
    }
}

int solve(const int &u, const int &p = 0){
    int sizes = 1, d;

    for(auto v : grafo[u]){
        if(v.f == p) continue;

        solve(v.f, u);

        sizes += siz[v.f];

        d = v.s;

        for(int i=sizes; i>=2; i--){
            for(int j=max(0, i-sizes+siz[v.f]); j<=min(i, siz[v.f]); j++){
                dp[u][i][0] = min({dp[u][i][0], dp[u][i-j][0] + dp[v.f][j][1]
                + 2*d, dp[u][i-j][1] + dp[v.f][j][0] + d});
                dp[u][i][1] = min({dp[u][i][1], dp[u][i-j][1] + dp[v.f][j][1] + 2*d});
            }
        }
    }
}

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

    cin >> n >> k >> x;

    for(int i=1; i<n; i++){
        int u, v, d;

        cin >> u >> v >> d;

        grafo[u].push_back({v, d});
        grafo[v].push_back({u, d});
    }

    dfs(x);

    for(int i=1; i<=n; i++){
        for(int j=2; j<=siz[i]; j++){
            dp[i][j][0] = dp[i][j][1] = inf;
        }
    }

    solve(x);

    cout << dp[x][k][0] << endl;

    return 0;
}

Compilation message

museum.cpp:8:0: warning: ignoring #pragma "Ofast"  [-Wunknown-pragmas]
 #pragma "Ofast"
 
museum.cpp: In function 'int solve(const int&, const int&)':
museum.cpp:50:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 640 KB Output is correct
2 Correct 4 ms 640 KB Output is correct
3 Correct 5 ms 640 KB Output is correct
4 Correct 5 ms 640 KB Output is correct
5 Correct 5 ms 640 KB Output is correct

Subtask #2
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 558 ms 28920 KB Output is correct
2 Correct 560 ms 29056 KB Output is correct
3 Correct 852 ms 165240 KB Output is correct
4 Correct 667 ms 73080 KB Output is correct
5 Correct 577 ms 40312 KB Output is correct

Subtask #3
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 558 ms 28920 KB Output is correct
2 Correct 560 ms 29056 KB Output is correct
3 Correct 852 ms 165240 KB Output is correct
4 Correct 667 ms 73080 KB Output is correct
5 Correct 577 ms 40312 KB Output is correct
6 Correct 561 ms 23424 KB Output is correct
7 Correct 738 ms 107768 KB Output is correct
8 Correct 1089 ms 2688 KB Output is correct
9 Correct 886 ms 3064 KB Output is correct
10 Correct 591 ms 3876 KB Output is correct

Subtask #4
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 640 KB Output is correct
2 Correct 4 ms 640 KB Output is correct
3 Correct 5 ms 640 KB Output is correct
4 Correct 5 ms 640 KB Output is correct
5 Correct 5 ms 640 KB Output is correct
6 Correct 558 ms 28920 KB Output is correct
7 Correct 560 ms 29056 KB Output is correct
8 Correct 852 ms 165240 KB Output is correct
9 Correct 667 ms 73080 KB Output is correct
10 Correct 577 ms 40312 KB Output is correct
11 Correct 561 ms 23424 KB Output is correct
12 Correct 738 ms 107768 KB Output is correct
13 Correct 1089 ms 2688 KB Output is correct
14 Correct 886 ms 3064 KB Output is correct
15 Correct 591 ms 3876 KB Output is correct
16 Correct 558 ms 29668 KB Output is correct
17 Correct 556 ms 29184 KB Output is correct
18 Correct 682 ms 82680 KB Output is correct
19 Correct 928 ms 2812 KB Output is correct
20 Correct 572 ms 4856 KB Output is correct
21 Correct 720 ms 106104 KB Output is correct
22 Correct 545 ms 29176 KB Output is correct
23 Correct 929 ms 2936 KB Output is correct
24 Correct 559 ms 4728 KB Output is correct
25 Correct 873 ms 169980 KB Output is correct