Submission #639993

#	Time	Username	Problem	Language	Result	Execution time	Memory
639993		colossal_pepe	Power Plant (JOI20_power)	C++17	0 / 100	1 ms	212 KiB

power

#include <iostream>
#include <vector>
#include <map>
using namespace std;

int n;
vector<pair<int, int>> edges;
vector<vector<int>> g;
vector<map<int, int>> dp;
string s;

int dfs(int u, int par) {
    if (dp[u].find(par) != dp[u].end()) return dp[u][par];
    int ret = 0;
    for (int v : g[u]) {
        if (v != par) ret += dfs(v, u);
    }
    if (s[u] == '1') ret = max(1, ret - 1);
    dp[u][par] = ret;
    return ret;
}

int solve() {
    dp.resize(n);
    int ans = 0;
    for (auto [a, b] : edges) {
        ans = max(ans, dfs(a, b) + dfs(b, a));
    }
    return ans;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n;
    edges.resize(n - 1), g.resize(n);
    for (auto &[a, b] : edges) {
        cin >> a >> b;
        a--, b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    cin >> s;
    cout << solve() << '\n';
    return 0;
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53