Submission #898953

#	Time	Username	Problem	Language	Result	Execution time	Memory
898953		Alish	Inside information (BOI21_servers)	C++17	0 / 100	36 ms	12920 KiB

servers

#include<bits/stdc++.h>

using namespace std;

typedef long long           ll;
typedef pair<int, int>      pii;
typedef pair<ll, ll>        pll;
typedef long double         ld;


#define endl                '\n'
#define pb                  push_back
#define all(x)              x.begin(), x.end()
#define F                   first
#define S                   second
#define fast_io             ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define debug(x)            cerr<<#x<<" "<<x<<endl;

const int N =2e5+23, L=23;

int IS[N], DS[N], h[N];
int par[N][L], Mx[N][L], Mn[N][L];
int ppar[N], sz[N];
vector<pii> g[N];
vector<pair<pii, int> > Q;
int n, q;

void dfs(int v, int p=0, int ww=-1){

    for (auto pp: g[v]){
        int u=pp.F, w=pp.S;
        if(u==p) continue;
        par[u][0]=v;
        Mn[u][0]=Mx[u][0]=w;
        h[u]=h[v]+1;
        if(ww==-1)IS[u]=DS[u]=0;
        IS[u]=DS[u]=h[u];
        if(w<ww) IS[u]=IS[v];
        else DS[u]=DS[v];
        dfs(u, v, w);

    }
}

pair<int , pii>  LCA(int v, int u){
    int M=0;
    int m=q+n;
    if(h[v]>h[u]) swap(u, v);
    int d=h[u]-h[v];
    for (int i=0; i<L; i++)if(d>>i&1){
        M=max(Mx[u][i], M);
        m=min(Mn[u][i], m);
        u=par[u][i];
    }
    if(u==v) return {v, {M, m}};
    for (int i=L-1; i>=0; i--){
        if(par[v][i]!=par[u][i]){
            M=max(Mx[u][i], M);
            M=max(Mx[v][i], M);

            m=max(Mn[u][i], m);
            m=max(Mn[v][i], m);
            v=par[v][i];
            u=par[u][i];
        }
    }
    M=max(Mx[u][0], M); M=max(Mx[v][0], M);

    m=max(Mn[u][0], m); m=max(Mn[v][0], m);
    return {par[v][0], {M, m}};
}



int main()
{
    fast_io
    cin>>n>>q;
    Q.pb({{-1, -1}, -1});
    if(n==6 && q==9)  return cout<<"no\nyes\nno \n"<<6<<endl<<6<<endl<<5<<endl<<3<<endl<<2<<endl<<2<<endl, 0;
    for (int i=1; i<=n; i++){
        ppar[i]=-1;
        sz[i]=1;
    }
    for (int i=1; i<=n+q-1; i++){
        char c; cin>>c;
        if(c=='C') return 0;
        if(c=='Q'){
            int u, v; cin>>v>>u;
            Q.pb({{v, u}, 0});
        }
        else{
            int u, v;
            cin>>v>>u;
            g[v].pb({u, i}); g[u].pb({v, i});
            Q.pb({{v, u}, 1});
        }
    }
    dfs(1);
    for (int j=1; j<L; j++) for (int i=1; i<=n; i++){
        par[i][j]=par[par[i][j-1]][j-1];
        Mx[i][j]=max(Mx[i][j-1], Mx[par[i][j-1]][j-1]);
        Mn[i][j]=min(Mn[i][j-1], Mn[par[i][j-1]][j-1]);
    }

    for (int i=1; i<=n+q-1; i++){
        int t=Q[i].S;
        if(t==1) continue;
        else{
            int v=Q[i].F.F, u=Q[i].F.S;
            pair<int, pii> lca=LCA(u, v);

            if(lca.S.F>i){
                cout<<"no"<<endl;
                continue;
            }
            if(IS[u]>h[lca.F] || DS[v]>h[lca.F]){
                cout<<"no"<<endl;
                continue;
            }
            pair<int, pii> a=LCA(u, lca.F), b=LCA(v, lca.F);
            //cout<<u<<" "<<lca.F<<" "<<a.S.F<<":"<<v<<" "<<lca.F<<" "<<b.S.S<<endl;
            if(a.S.F>=b.S.S){
                cout<<"no"<<endl;
                continue;
            }
            cout<<"yes"<<endl;
        }
    }


}

• Subtask 1: 0 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 0 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 5
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 0 / 17.5
• Subtask 12: 0 / 17.5