Submission #863584

#	Time	Username	Problem	Language	Result	Execution time	Memory
863584		Ahmed_Solyman	Inside information (BOI21_servers)	C++14	0 / 100	2 ms	348 KiB

servers

/*
In the name of Allah
made by: Ahmed_Solyman
*/
#include <bits/stdc++.h>
#include <ext/rope>
 
using namespace std;
using namespace __gnu_cxx;
#pragma GCC optimize("-Ofast")
#pragma GCC optimize("-O1")
//-------------------------------------------------------------//
typedef long long ll;
typedef unsigned long long ull;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define PI acos(-1)
#define lb lower_bound
#define ub upper_bound
#define endl '\n'
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define sum_to(n) (n*(n+1))/2
#define pb push_back
#define pf push_front
#define fil(arr,x) memset(arr,x,sizeof(arr))
const ll mod=1e9+7;
int dx[8]={0,1,0,-1,1,1,-1,-1};
int dy[8]={1,0,-1,0,1,-1,-1,1};
//-------------------------------------------------------------//
ll lcm(ll a,ll b)
{
    return (max(a,b)/__gcd(a,b))*min(a,b);
}
void person_bool(bool x)
{
    cout<<(x?"yes":"no")<<endl;
}
struct DSU{
    vector<int>P,sz,t;
    void init(int n){
        P.resize(n+5);
        sz.assign(n+5,1);
        t.resize(n+5);
        for(int i=0;i<n+5;i++)P[i]=i;
    }
    int find(int node,int time){
        if(P[node]==node || t[node]>time)return node;
        return P[node]=find(P[node],time);
    }
    bool unite(int a,int b,int time){
        int p1=find(a,time);
        int p2=find(b,time);
        if(p1==p2){
            return 0;
        }
        if(sz[p1]>sz[p2]){
            swap(p1,p2);
        }
        P[p1]=p2;
        sz[p2]+=sz[p1];
        t[p1]=time;
        return 1;
    }
}d;
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    #ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    freopen("output.out", "w", stdout);
    #endif
    fast
    int n,q;cin>>n>>q;
    d.init(n+5);q+=n;
    q--;
    int cnt=1;
    vector<int>u(n+1),v(n+1);
    while(q--){
        char c;cin>>c;
        if(c=='S'){
            int a,b;cin>>a>>b;
            u[cnt]=a;v[cnt]=b;
            d.unite(a,b,cnt++);
        }
        else if(c=='Q'){
            int a,b;cin>>a>>b;
            int l=1,r=cnt-1;
            int e=-1;
            while(l<=r){
                int mid=l+r>>1;
                if(d.find(a,mid)==d.find(b,mid)){
                    e=mid;
                    r=mid-1;
                }
                else{
                    l=mid+1;
                }
            }
            if(e==-1){
                cout<<"no"<<endl;
                continue;
            }
            if(a==u[e] || a==v[e]){
                cout<<"yes"<<endl;
            }
            else{
                cout<<"no"<<endl;
            }
        }
        else{
            int u;cin>>u;
        }
    }
    return 0;
}

Compilation message (stderr)

servers.cpp: In function 'int main()':
servers.cpp:91:26: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   91 |                 int mid=l+r>>1;
      |                         ~^~
servers.cpp:70:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |     freopen("input.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
servers.cpp:71:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |     freopen("output.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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