Primality Test Problem: PRB01

Primality Test Problem Codechef Solution

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Alice and Bob are meeting after a long time. As usual they love to play some math games. This times Alice takes the call and decides the game. The game is very simple, Alice says out an integer and Bob has to say whether the number is prime or not. Bob as usual knows the logic but since Alice doesn’t give Bob much time to think, so Bob decides to write a computer program.

Primality Test Problem Codechef Solution

Help Bob accomplish this task by writing a computer program which will calculate whether the number is prime or not .

Input

The first line of the input contains an integer T, the number of testcases. T lines follow.

Each of the next T lines contains an integer N which has to be tested for primality.

Output

For each test case output in a separate line, “yes” if the number is prime else “no.”

Constraints

• 1 ≤ T ≤ 20
• 1 ≤ N ≤ 100000

Sample Input 1 

5
23
13
20
1000
99991

Sample Output 1 

yes
yes
no
no
yes

Primality Test Problem Codechef Solution in JAVA

/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner sc=new Scanner(System.in);
		int t=sc.nextInt();
		while(t-->0){
		    int n=sc.nextInt();
		    boolean flag=false;
		    if(n==1){
		        System.out.println("no");
		        continue;
		    }
		    if(n==2){
		        System.out.println("yes");
		        continue;
		    }
		    for(int i=2;i< n/2;i++){
		        if(n%i==0){
		            flag =true;
		            break;
		        }

		    }
		    if(!flag){
		        System.out.println("yes");
		    }
		    else
		        System.out.println("no");
		}// your code goes here
	}
}

Primality Test Problem Codechef Solution in C++ 14

int main() {
    int t;
    cin>>t;
    while(t--){
           int n , c = 0;
           cin>>n;
           for(int i = 1 ; i <= n; i++){
            if(n/i != 0 && n%i == 0){
                c++;
            }
           }
           if(c == 2){
            cout<< "yes"<< endl;
           }
           else{
            cout << "no"<< endl;
           }
    }
    return 0;
}

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This is Primality Test Problem Codechef Solution