GCDGCD - Editorial

Problem Link:

Practice

Contest

Author: Niket Agarwal

Tester: Pritish Priyatosh Nayak

Editorialist: Niket Agawal

Difficulty:

Cakewalk

Prerequisites:

Hash Table

Problem:

Given an array of integers. Find the minimum number of subsequences the array can be divided to such that no two subsequences contain the same element.

Explanation:

Count the frequency of each element given. Since the range of A[I] was below 1e6.
A simple hash table (frequency array) could be used to count.
The answer was the maximum frequency.

Solutions:

Setter's/Editorialist's Solution
import java.util.*;import java.io.*;import java.math.*;
public class Main
{
    public static void process()throws IOException
    {
        int n=ni();
        int[]freq=new int[(int)1e6+1];
        for(int i=0;i<n;i++)
            freq[ni()]++;
        Arrays.sort(freq);
        pn(freq[(int)1e6]);
    }
    static AnotherReader sc;
    static PrintWriter out;
    public static void main(String[]args)throws IOException
    {
        boolean oj = true;
        if(oj){sc=new AnotherReader();out=new PrintWriter(System.out);}
        else{sc=new AnotherReader(100);out=new PrintWriter("output.txt");}
        int t=1;
        t=ni();
        while(t-->0) {process();}
        out.flush();out.close();  
    }
 
    static void pn(Object o){out.println(o);}
    static void p(Object o){out.print(o);}
    static void pni(Object o){out.println(o);out.flush();}
    static int ni()throws IOException{return sc.nextInt();}
    static long nl()throws IOException{return sc.nextLong();}
    static double nd()throws IOException{return sc.nextDouble();}
    static String nln()throws IOException{return sc.nextLine();}
    static int[] nai(int N)throws IOException{int[]A=new int[N];for(int i=0;i!=N;i++){A[i]=ni();}return A;}
    static long[] nal(int N)throws IOException{long[]A=new long[N];for(int i=0;i!=N;i++){A[i]=nl();}return A;}
    static long gcd(long a, long b)throws IOException{return (b==0)?a:gcd(b,a%b);}
    static int gcd(int a, int b)throws IOException{return (b==0)?a:gcd(b,a%b);}
    static int bit(long n)throws IOException{return (n==0)?0:(1+bit(n&(n-1)));}
 
/////////////////////////////////////////////////////////////////////////////////////////////////////////
 
    static class AnotherReader{BufferedReader br; StringTokenizer st;
    AnotherReader()throws FileNotFoundException{
    br=new BufferedReader(new InputStreamReader(System.in));}
    AnotherReader(int a)throws FileNotFoundException{
    br = new BufferedReader(new FileReader("input.txt"));}
    String next()throws IOException{
    while (st == null || !st.hasMoreElements()) {try{
    st = new StringTokenizer(br.readLine());}
    catch (IOException  e){ e.printStackTrace(); }}
    return st.nextToken(); } int nextInt() throws IOException{
    return Integer.parseInt(next());}
    long nextLong() throws IOException
    {return Long.parseLong(next());}
    double nextDouble()throws IOException { return Double.parseDouble(next()); }
    String nextLine() throws IOException{ String str = ""; try{
    str = br.readLine();} catch (IOException e){
    e.printStackTrace();} return str;}}
   
/////////////////////////////////////////////////////////////////////////////////////////////////////////////
} 
Tester's Solution
#include<bits/stdc++.h>
using namespace std;
int main()
{
   ios_base::sync_with_stdio(false);cin.tie(NULL);
   #ifdef Zoro
   freopen("/home/pritish/Competitive/in", "r", stdin);
   freopen("/home/pritish/Competitive/out", "w", stdout);
   #endif
 
   int t;
   cin>>t;
   assert(t>=1&&t<=1000);
   int sumn=0;
   while(t--)
   {
      int n;
      cin>>n;
      assert(n>=1&&n<=1000);
      sumn+=n;
      assert(sumn>=1&&sumn<=1000);
 
      map<int,int> mpp;
      for (int i = 0; i < n; ++i)
      {
         int x;
         cin>>x;
         assert(x<=1e6&&x>=1);
         mpp[x]++;
      }
      int ans=0;
      for(auto &[x,y]:mpp)
         ans=max(ans,y);
 
      cout<<ans<<'\n';
   }
 
   cerr<<"\n"<<(float)clock()/CLOCKS_PER_SEC*1000<<" ms"<<endl;
   return 0;
}