Submission #898995

#	Time	Username	Problem	Language	Result	Execution time	Memory
898995		Alish	Inside information (BOI21_servers)	C++14	0 / 100	35 ms	12752 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;
const int INF=1e9+23;
int IS[N], DS[N], h[N];
int par[N][L], st[N], ft[N], tim;
int up[N];
vector<pii> g[N];
int n, q;
vector<pair<pii, int>> Q;


void dfs(int v, int p=1){
    st[v]=tim++;
    for (auto pp: g[v]){
        int u=pp.F, w=pp.S;
        if(u==p) continue;
        IS[u]=DS[u]=v;
        up[u]=w;
        par[u][0]=v;
        if(up[u]<up[v]) IS[u]=IS[v];
        else DS[u]=DS[v];
        dfs(u, v);
    }
    ft[v]=tim;
}

int jmp(int v, int d){
    for (int i=0; i<L; i++) if(d>>i&1) v=par[v][i];
    return v;
}

int D(int v, int u){

    int tu=u, tv=v;
    if(st[v]<=st[u] && ft[v]>=ft[u]) return up[u];
    int f=0;

    for (int i=L-1; i>=0; i--){
        if(!(st[par[u][i]]<=st[v] && ft[par[u][i]]>=ft[v])) u=par[u][i];
        if(!(st[par[v][i]]<=st[u] && ft[par[v][i]]>=ft[u])) v=par[v][i];
    }

    if(up[v]>up[u]) return INF;
    return up[tu];


}

bool ok(int v, int u, int i){
    if(!(st[IS[v]]<=st[u] && ft[IS[v]]>=ft[u]))return 0;
    if(!(st[DS[u]]<=st[v] && ft[DS[u]]>=ft[v]))return 0;
    if(D(v, u)<=i) return 1;
    return 0;

}

int main()
{
    fast_io
    Q.pb({{-1, -1}, -1});
    cin>>n>>q;
    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});
        }
    }
    IS[1]=DS[1]=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];


    for (int i=1; i<=n+q-1; i++){
        int t=Q[i].S;
        if(t==1) continue;
        else{
            int u=Q[i].F.S, v=Q[i].F.F;
            if(ok(u, v, i))cout<<"yes"<<endl;
            else cout<<"no"<<endl;
        }
    }
}

Compilation message (stderr)

servers.cpp: In function 'int D(int, int)':
servers.cpp:51:15: warning: unused variable 'tv' [-Wunused-variable]
   51 |     int tu=u, tv=v;
      |               ^~
servers.cpp:53:9: warning: unused variable 'f' [-Wunused-variable]
   53 |     int f=0;
      |         ^

• 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