Submission #539008

#	Time	Username	Problem	Language	Result	Execution time	Memory
539008		ddy888	Power Plant (JOI20_power)	C++17	100 / 100	183 ms	32324 KiB

power

#undef _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb push_back
#define fi first
#define si second
#define ar array
using lint = long long;
typedef pair<int,int> pi;
typedef tuple<int,int,int> ti;  
void debug_out() {cerr<<endl;}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {cerr<<" "<<to_string(H);debug_out(T...);}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:",debug_out(__VA_ARGS__)

int N, ans;
vector<int> adj[200010];
char S[200010];
int dp[200010][2];

void dfs(int x, int p) {
    int sum = 0, mx = 0;
    for (auto i: adj[x]) {
        if (i == p) continue;
        dfs(i, x);
        sum += dp[i][0];
        mx = max(mx, dp[i][0]);
    }
    if (S[x] == '1') {
        dp[x][1] = max(mx + 1, 1);
        dp[x][0] = max(sum - 1, 1);
    } else {
        dp[x][0] = sum;
        dp[x][1] = sum;
    }
}

int main() {
    fast;
    cin >> N;
    for (int i = 1; i < N; ++i) {
        int u, v; cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    for (int i = 1; i <= N; ++i) cin >> S[i];
    dfs(1, -1);
    for (int i = 1; i <= N; ++i) ans = max({ans, dp[i][0], dp[i][1]});
    cout << ans;
    return 0;
}

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