Submission #868672

#	Time	Username	Problem	Language	Result	Execution time	Memory
868672		sleepntsheep	Power Plant (JOI20_power)	C++17	0 / 100	1 ms	6492 KiB

power

#include <cstdio>
#include <cstring>
#include <cassert>
#include <string>
#include <deque>
#include <vector>
#include <map>
#include <queue>
#include <algorithm>
#include <iostream>
#include <utility>
using namespace std;
using ll = long long;
using ld = long double;
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false)

#define N 200005
#define ALL(x) x.begin(), x.end()

int n, ans, f[N], h[N], pwr[N];
vector<int> g[N];
char s[N];

void dfs(int u, int p)
{
    if (s[u]=='1')++pwr[u], f[u]=h[u]=1;
    int C=0;
    for (auto v : g[u]) if (v^p) 
    {
        dfs(v, u);
        pwr[u] += pwr[v];
        C+=!!pwr[v];
        f[u]+=f[v];
    }
    if (s[u]=='1')
    {
        f[u]=max(f[u]-1, 1);
    }
}

void dfs2(int u, int p)
{
    for (auto v : g[u]) if (v^p)
    {
        if (s[v]=='1')h[v]=1;
        int sib=0;
        if(s[u]=='1')
        {
            sib=max(1, f[u]-f[v]);
        }
        else sib=f[u]-f[v];
        h[v]=max(h[v], sib);
        dfs2(v, u);
    }
}

int main()
{
    ShinLena;
    cin >> n;
    for (int i = 1, u, v; i < n; ++i) cin >> u >> v, g[u].push_back(v), g[v].push_back(u);
    cin >> (s+1);
    dfs(1, 1);
    for(int i=1;i<=n;++i)ans=max(ans,f[i]+h[i]);
    cout<<ans;

    return 0;
}

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