oj.uz

답안 #429524

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
429524 2021-06-16T05:15:54 Z dxz05 Power Plant (JOI20_power) C++14
0 / 100
 5 ms 5660 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int N = 222222;

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

vector<int> g[N];
int dp[N][2];
bool lamp[N];

void dfs(int v, int p){
    dp[v][1] = lamp[v];
    int sum = (lamp[v] ? -1 : 0);
    for (int u : g[v]){
        if (u == p) continue;
        dfs(u, v);
        if (lamp[u]){
            sum += max({1, dp[u][0], dp[u][1] - lamp[u]});
        } else sum += dp[u][0];
        dp[v][0] = max({dp[v][0], dp[u][0], dp[u][1]});
        dp[v][1] = max({dp[v][1], dp[u][0] + 1, dp[u][1]});
    }

    dp[v][0] = max(dp[v][0], sum - lamp[v]);
    if (!lamp[v]) dp[v][1] = 0;
}

void solve(){
    int n;
    cin >> n;

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

    string s;
    cin >> s;
    for (int i = 0; i < n; i++) lamp[i + 1] = s[i] == '1';

    dfs(1, 1);

    //for (int i = 1; i <= n; i++) cout << i << ' ' << dp[i][0] << ' ' << dp[i][1] << endl; cout << endl;

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

}

int main(){
    //freopen("output.txt", "w", stdout);
    int tests = 1;
    //cin >> tests;

    while (tests--){
        solve();
    }

    return 0;
}

Subtask #1
0.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5452 KB Output is correct
2 Correct 4 ms 5660 KB Output is correct
3 Correct 5 ms 5452 KB Output is correct
4 Correct 4 ms 5532 KB Output is correct
5 Incorrect 4 ms 5532 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5452 KB Output is correct
2 Correct 4 ms 5660 KB Output is correct
3 Correct 5 ms 5452 KB Output is correct
4 Correct 4 ms 5532 KB Output is correct
5 Incorrect 4 ms 5532 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0.0 / 53.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5452 KB Output is correct
2 Correct 4 ms 5660 KB Output is correct
3 Correct 5 ms 5452 KB Output is correct
4 Correct 4 ms 5532 KB Output is correct
5 Incorrect 4 ms 5532 KB Output isn't correct
6 Halted 0 ms 0 KB -