Submission #935538

#	Time	Username	Problem	Language	Result	Execution time	Memory
935538		Whisper	Power Plant (JOI20_power)	C++17	100 / 100	147 ms	28392 KiB

power

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define pii pair<int , int>
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
int numNode;
vector<int> adj[MAX];
string s;
int dp[MAX];
int hasGen[MAX];
int ans = 0;
void dfs(int u, int p){
    int pre_ans = 0;
    for (auto&v : adj[u]) if(v ^ p){
        dfs(v, u);
        dp[u] += dp[v];
        maximize(pre_ans, dp[v]);
    }
    if (hasGen[u]){
        dp[u] = max(dp[u] - 1, 1ll);
        pre_ans++;
    }
    maximize(ans, max(pre_ans, dp[u]));
}
void Whisper(){
    cin >> numNode;
    for (int i = 1; i < numNode; ++i){
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    cin >> s;
    REP(i, numNode){
        hasGen[i + 1] = (s[i] == '1');
    }
    dfs(1, 0);
    cout << ans;
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

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