Submission #1098067

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098067		TrinhKhanhDung	Power Plant (JOI20_power)	C++14	0 / 100	3 ms	5160 KiB

power

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define sz(x) (int)x.size()
#define ALL(v) v.begin(),v.end()
#define MASK(k) (1LL << (k))
#define BIT(x, i) (((x) >> (i)) & 1)
#define oo (ll)1e18
#define INF (ll)1e9
#define MOD (ll)(1e9 + 7)

using namespace std;

template<class T1, class T2>
    bool maximize(T1 &a, T2 b){if(a < b){a = b; return true;} return false;}

template<class T1, class T2>
    bool minimize(T1 &a, T2 b){if(a > b){a = b; return true;} return false;}

template<class T1, class T2>
    void add(T1 &a, T2 b){a += b; if(a >= MOD) a -= MOD;}

template<class T1, class T2>
    void sub(T1 &a, T2 b){a -= b; if(a < 0) a += MOD;}

template<class T>
    void cps(T &v){sort(ALL(v)); v.resize(unique(ALL(v)) - v.begin());}

const int MAX = 2e5 + 10;

int N, ans;
vector<int> adj[MAX];
int f[MAX];
string s;

void dfs(int u, int p = -1){
    int sum = 0;
    int ma = 0;
    for(int v: adj[u]){
        if(v == p) continue;
        dfs(v, u);
        sum += f[v];
        maximize(ma, f[v]);
    }
    f[u] = max((int)(s[u] == '1'), sum - (s[u] == '1'));
    maximize(ans, sum);
    maximize(ans, ma + (s[u] == '1'));
//    cout << u << ' ' << f[u] << '\n';
}

void solve(){
    cin >> N;
    for(int i = 1; i < N; i++){
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    cin >> s;
    s = "*" + s;
    dfs(1);
    cout << ans << '\n';
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
//     freopen("btower.inp","r",stdin);
//     freopen("btower.out","w",stdout);

    int t = 1;
//    cin >> t;
    while(t--){
        solve();
    }

    return 0;
}

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