Submission #1197361

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197361		Captain_Georgia	Power Plant (JOI20_power)	C++20	100 / 100	175 ms	31600 KiB

power

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

int32_t main () {

    ios_base::sync_with_stdio(0); 
    cin.tie(0); 
    cout.tie(0); 

    int N;
    cin >> N;
    vector<int> g[N];
    for (int i = 1;i < N;i ++) {
        int u, v;
        cin >> u >> v;
        -- u; -- v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    string S;
    cin >> S;

    int mx = 0;
    vector<int> dp(N, 0);
    function<void(int, int)> dfs_init = [&](int si, int pi) -> void {
        int tmp = 0;
        for (auto ti : g[si]) if (ti != pi) {
            dfs_init(ti, si);
            tmp += dp[ti];
        }
        if (g[0].size() == 1 && si == 0) {
            dp[si] = max(S[si] - '0', tmp + (S[si] - '0'));
        } else {
            dp[si] = max(S[si] - '0', tmp - (S[si] - '0'));
        }
    };
    dfs_init(0, 0);

    function<void(int, int, int)> dfs = [&](int si, int pi, int val) -> void {
        for (auto ti : g[si]) if (ti != pi) {
            val += dp[ti];
        }
        if (g[si].size() == 1) mx = max(mx, val + (S[si] - '0'));
        else mx = max(mx, max(S[si] - '0', val - (S[si] - '0')));
        for (auto ti : g[si]) if (ti != pi) {
            dfs(ti, si, max(val - dp[ti] - (S[si] - '0'), S[si] - '0'));
        }
    };
    dfs(0, 0, 0);
    cout << mx << "\n";
}

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53