Submission #870870

#	Time	Username	Problem	Language	Result	Execution time	Memory
870870		Rafi22	Svjetlo (COCI20_svjetlo)	C++14	20 / 110	13 ms	2308 KiB

svjetlo

#include <bits/stdc++.h>

#define ll long long
#define ld double
#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
using namespace std;
int inf=1000000007;
int mod=1000000007;
int mod1=998244353;

const int N=107;

vector<int>G[N];
bool is[N],t[N],x[N];
bool nie[N];

void dfs(int v,int o,int k)
{
    t[v]=!is[v];
    x[v]=is[v];
    nie[v]=(v==k);
    for(auto u:G[v])
    {
        if(u==o) continue;
        dfs(u,v,k);
        t[v]|=t[u];
        nie[v]|=nie[u];
    }
}
int cnt;
void dfs1(int v,int o)
{
    x[v]^=1;
    cnt++;
    int ile=0;
    for(auto u:G[v])
    {
        if(u==o||!t[u]) continue;
        dfs1(u,v);
        if(!nie[u]) ile++;
    }
    cnt+=ile;
    x[v]^=(ile%2);
    if(x[v]==0)
    {
        if(o==0) cnt=inf;
        else
        {
            cnt+=2;
            x[v]^=1;
            x[o]^=1;
        }
    }
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n,a,b;
    string s;
    cin>>n>>s;
    for(int i=0;i<n;i++) is[i+1]=s[i]-'0';
    for(int i=1;i<n;i++)
    {
        cin>>a>>b;
        G[a].pb(b);
        G[b].pb(a);
    }
    int ans=inf;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            dfs(i,0,j);
            cnt=0;
            dfs1(i,0);
            ans=min(ans,cnt);
        }
    }
    cout<<ans;


    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 30
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30