Submission #766003

#	Time	Username	Problem	Language	Result	Execution time	Memory
766003		Owen11	Power Plant (JOI20_power)	C++14	0 / 100	3 ms	5024 KiB

power

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

# define int long long
# define fir first
# define sec second
# define pb push_back

const int cnst = 2e5+5;
bool mutipletestcase = 0;
//bool debug = false;

vector<int> vec[cnst];
bool id[cnst];
int par[cnst];
int counts[cnst];
int ans = 0;

void dfs(int x) {
    int y = 0;
    int fre = 0;
    for(auto v: vec[x]) {
        if(v == par[x]) continue;
        par[v] = x;
        dfs(v);
        y += counts[v];
        if(counts[v]) fre++;
    }
    if(!id[x]) counts[x] = y;
    else counts[x] = max(y-1, 1ll); 
    
    if(fre == 1) ans = max(ans, y+id[x]);
    else ans = max(ans, y-id[x]);
}

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

    for(int i = 1; i<n; i++) {
        int a, b; cin >> a >> b;
        vec[a].pb(b);
        vec[b].pb(a);
    }

    string s; cin >> s;

    for(int i = 0; i<n; i++) {
        id[i+1] = (s[i] == '1');
    }

    dfs(1);

    cout << ans << endl;
}

signed main() {
    ios_base::sync_with_stdio(false);
    int t = 1;
    if(mutipletestcase) cin >> t; 
    while(t--) solve();
}

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