Submission #577159

#	Time	Username	Problem	Language	Result	Execution time	Memory
577159		Valters07	Inside information (BOI21_servers)	C++14	53 / 100	196 ms	32716 KiB

servers

#include <bits/stdc++.h>
#pragma GCC optimize ("O2,unroll-loops")
#define fio ios_base::sync_with_stdio(0);cin.tie(0);
#define ll long long
#define en cin.close();return 0;
#define pb push_back
#define fi first//printf("%lli\n",cur);
#define se second//scanf("%lli",&n);
#define r0 return 0;
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 120005;
const int LOG = log2(N)+2;
vector<pair<int,int> > g[N];
int par[N][LOG], tin[N], tout[N], tt;
int down[N], up[N], dep[N];
int topar[N];
void dfs(int u, int p)
{
    tin[u]=++tt;
    par[u][0]=p;
    for(int i = 1;i<LOG;i++)
        par[u][i]=par[par[u][i-1]][i-1];
    for(auto v:g[u])
    {
        if(v.fi!=p)
        {
            topar[v.fi]=v.se;
            down[v.fi]=(v.se>topar[u]||u==1?down[u]+1:1);
            up[v.fi]=(v.se<topar[u]||u==1?up[u]+1:1);
            dep[v.fi]=dep[u]+1;
            dfs(v.fi,u);
        }
    }
    tout[u]=tt;
}
bool is_anc(int u, int v)
{
    return (tin[u]<=tin[v]&&tout[v]<=tout[u]);
}
int main()
{
    fio
    //ifstream cin("in.in");
    int n, q;
    cin >> n >> q;
    vector<pair<pair<int,int>,int> > qu;
    for(int i = 1;i<n+q;i++)
    {
        char c;
        cin >> c;
        if(c=='C')
            return 0;
        int u, v;
        cin >> u >> v;
        if(c=='Q')
            qu.pb({{u,v},i});
        else
            g[u].pb({v,i}),
            g[v].pb({u,i});
    }
    dfs(1,1);
    for(auto i:qu)
    {
        int u = i.fi.fi, v = i.fi.se, t = i.se;
        swap(u,v);
        if(u==v)
            cout << "yes";
        else if(is_anc(u,v))
            cout << ((dep[v]-dep[u])<=down[v]&&topar[v]<t?"yes":"no");
        else if(is_anc(v,u))
        {
            int u1 = u;
            for(int i = LOG-1;i>=0;i--)
                if(!is_anc(par[u1][i],v))
                    u1=par[u1][i];
            cout << ((dep[u]-dep[v])<=up[u]&&topar[u1]<t?"yes":"no");
        }
        else
        {
            int u1 = u, v1 = v;
            for(int i = LOG-1;i>=0;i--)
            {
                if(!is_anc(par[u1][i],v))
                    u1=par[u1][i];
                if(!is_anc(par[v1][i],u))
                    v1=par[v1][i];
            }
            int lca = par[u1][0];
            cout << (dep[u]-dep[lca]<=up[u]&&dep[v]-dep[lca]<=down[v]&&
                     topar[u1]<topar[v1]&&topar[v]<t?"yes":"no");
        }
        cout << "\n";
    }
    //cin.close();
    return 0;
}

• Subtask 1: 2.5 / 2.5
• Subtask 2: 0.5 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 0.5 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 0.5 / 5
• Subtask 7: 10 / 10
• Subtask 8: 0.5 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 0.5 / 12.5
• Subtask 11: 17.5 / 17.5
• Subtask 12: 0.5 / 17.5