c_cpp 旅行很有趣

Posted 2021-05-14

//https://www.hackerrank.com/contests/hack-it-to-win-it-paypal/challenges/q4-traveling-is-fun/problem
#include <bits/stdc++.h>
using namespace std;

void dfs (int s,vector < vector <int> > &adj, vector <int> &cc, int m) {
    cc[s]= m;
    for (int i=0;i<adj[s].size();i++)
        if (cc[adj[s][i]]==0)
            dfs(adj[s][i], adj,cc,m);
}

int main() {
    int n,g,q;
    cin>>n;
    cin>>g;
    cin>>q;
    int oc[q], dc[q];
    for (int i=0;i<q;i++)
        cin>>oc[i];
    cin>>q;
    for (int i=0;i<q;i++)
        cin>>dc[i];

    if (g==n) {
        for (int i=0;i<q;i++)
            cout<< 0<< "\n";
        return 0;
    }
    if (g==0) {
        for (int i=0;i<q;i++)
            cout<< 1<< "\n";
        return 0;
    }

    vector < vector <int> > adj(n+1);//construct the adjacency list
    for (int i=g+1; i<=n;i++) {//we have to check all the multiples of i>g
        for (int j=2;j*i<=n;j++) {
            int a= j*i;
            adj[a].push_back(i);
            adj[i].push_back(a);
        }
    }
    vector <int> cc(n+1,0);//vector to store the indices of connected components
    int m=1;
    for (int i=1;i<=n;i++) {
        if (cc[i]== 0) {
            dfs(i,adj, cc,m);
            m++;
        }
    }
    for (int i=0;i<q;i++) {
        if (cc[oc[i]]== cc[dc[i]])
            cout<< 1<< endl;
        else
            cout<< 0 << endl;
    }
    return 0;
}