Submission #781433

#	Time	Username	Problem	Language	Result	Execution time	Memory
781433		boris_mihov	Cat Exercise (JOI23_ho_t4)	C++17	31 / 100	2062 ms	16604 KiB

Main

#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>

typedef long long llong;
const int MAXN = 200000 + 10;
const int INF  = 1e9;

int n;
int d[MAXN];
int dp[MAXN];
std::vector <int> g[MAXN];

void getDist(int node, int p, int root)
{
    d[node] = d[p] + 1;
    for (const int &u : g[node])
    {
        if (u == p || u > root)
        {
            continue;
        }

        getDist(u, node, root);
    }
}

void solve()
{
    dp[1] = 0;
    for (int i = 2 ; i <= n ; ++i)
    {
        std::fill(d + 1, d + 1 + n, -INF); d[0] = -1;
        getDist(i, 0, i);

        for (int j = i - 1 ; j >= 1 ; --j)
        {
            dp[i] = std::max(dp[i], dp[j] + d[j]);
        }
    }

    std::cout << dp[n] << '\n';
}

void input()
{
    std::cin >> n;
    for (int i = 1 ; i <= n ; ++i)
    {
        std::cin >> d[i];
    }

    for (int i = 2 ; i <= n ; ++i)
    {
        int u, v;
        std::cin >> u >> v;
        g[d[u]].push_back(d[v]);
        g[d[v]].push_back(d[u]);
    }
}

void fastIOI()
{
    std::ios_base :: sync_with_stdio(0);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
}

int main()
{
    fastIOI();
    input();
    solve();

    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 10 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26