oj.uz

답안 #389122

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
389122 2021-04-13T16:54:30 Z phathnv 구슬과 끈 (APIO14_beads) C++11
0 / 100
 5 ms 5024 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int N = 2e5 + 7;
const int INF = 1e9 + 7;

struct Edge{
    int v, c;
    Edge(int _v, int _c){
        v = _v;
        c = _c;
    }
};

int n, dp[N][4];
vector<Edge> adj[N];

void Dfs(int u, int p){
    dp[u][0] = 0;
    dp[u][1] = -INF;
    dp[u][2] = -INF;
    dp[u][3] = -INF;
    for(Edge e : adj[u]){
        int v = e.v;
        int c = e.c;
        if (v == p)
            continue;
        Dfs(v, u);
        int nxtDp[4] = {-INF, -INF, -INF, -INF};

        nxtDp[0] = max(nxtDp[0], dp[u][0] + dp[v][0]);
        nxtDp[0] = max(nxtDp[0], dp[u][0] + dp[v][1] + c);
        nxtDp[0] = max(nxtDp[0], dp[u][0] + dp[v][3]);

        nxtDp[1] = max(nxtDp[1], dp[u][0] + dp[v][0] + c);
        nxtDp[1] = max(nxtDp[1], dp[u][1] + dp[v][0]);
        nxtDp[1] = max(nxtDp[1], dp[u][1] + dp[v][1] + c);
        nxtDp[1] = max(nxtDp[1], dp[u][1] + dp[v][3]);

        nxtDp[2] = max(nxtDp[2], dp[u][0] + dp[v][3] + c);
        nxtDp[2] = max(nxtDp[2], dp[u][2] + dp[v][0]);
        nxtDp[2] = max(nxtDp[2], dp[u][2] + dp[v][1] + c);
        nxtDp[2] = max(nxtDp[2], dp[u][2] + dp[v][3]);

        nxtDp[3] = max(nxtDp[3], dp[u][0] + dp[v][2] + c);
        nxtDp[3] = max(nxtDp[3], dp[u][1] + dp[v][0] + c);
        nxtDp[3] = max(nxtDp[3], dp[u][1] + dp[v][3] + c);
        nxtDp[3] = max(nxtDp[3], dp[u][2] + dp[v][0] + c);
        nxtDp[3] = max(nxtDp[3], dp[u][3] + dp[v][1] + c);
        nxtDp[3] = max(nxtDp[3], dp[u][3] + dp[v][3]);

        dp[u][0] = nxtDp[0];
        dp[u][1] = nxtDp[1];
        dp[u][2] = nxtDp[2];
        dp[u][3] = nxtDp[3];
    }
}

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

    cin >> n;
    for(int i = 1; i < n; i++){
        int u, v, c;
        cin >> u >> v >> c;
        adj[u].push_back(Edge(v, c));
        adj[v].push_back(Edge(u, c));
    }

    Dfs(1, -1);
    cout << max(dp[1][0], dp[1][3]);

    return 0;
}

Subtask #1
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 3 ms 5016 KB Output is correct
7 Correct 5 ms 4940 KB Output is correct
8 Correct 3 ms 4940 KB Output is correct
9 Correct 4 ms 5024 KB Output is correct
10 Incorrect 3 ms 5024 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 3 ms 5016 KB Output is correct
7 Correct 5 ms 4940 KB Output is correct
8 Correct 3 ms 4940 KB Output is correct
9 Correct 4 ms 5024 KB Output is correct
10 Incorrect 3 ms 5024 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 3 ms 5016 KB Output is correct
7 Correct 5 ms 4940 KB Output is correct
8 Correct 3 ms 4940 KB Output is correct
9 Correct 4 ms 5024 KB Output is correct
10 Incorrect 3 ms 5024 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 3 ms 5016 KB Output is correct
7 Correct 5 ms 4940 KB Output is correct
8 Correct 3 ms 4940 KB Output is correct
9 Correct 4 ms 5024 KB Output is correct
10 Incorrect 3 ms 5024 KB Output isn't correct
11 Halted 0 ms 0 KB -