CODEWITHSUNDEEP
javaif-statementfor-loopprimes
Jason arora
Jason arora

Reputation: 550

Given three numbers as input,return true if at least one of them is a prime number

Given three numbers as input, return true if at least one of them is a prime number. For solving this problem, define a function that checks whether a number is a prime or not and use that function

MyApproach:

I made a function that checks first whether the num is prime or not(CHECK PRIME).After checking the 3 numbers,if in that function any of the number is prime it should return true otherwise false.

But I am getting wrong Ans for the test case

Below is my Code:

public boolean anyonePrime(int num1, int num2, int num3)
{    
    boolean b1=checkPrime(num1);
    boolean b2=checkPrime(num2);
    boolean b3=checkPrime(num3);
    if((b1==true) ||(b2==true) ||(b3==true))  //@Edit
    return true;
    else 
    return false;
}    
public boolean checkPrime(int num)
{
    boolean b0=true;
    if(num==1)
        return false;  //@Edit
    else
    {
        for(int i=2; i<=num/2; i++)
        { 
            if(num % i==0)
            { 
                return false;   //@Edit
            }
        }
        return true;
    } 

    if(b0==true)
        return true;
    else 
        return false;
    //write your code here
    }   
}

@ Edit passes all test cases For the Input

Parameters          ActualOutput    Expected Output     
'169' '361' '529'   true            false

Upvotes: 2

Views: 1428

Answers (3)

ergonaut
ergonaut

Reputation: 7057

The main issue is that b0=true always. But..

  • it is also rather inefficient as you don't stop immediately if the first one is prime,
  • nor do you stop immediately if there is a divisor,
  • nor do you stop when you reach the square root of num
  • also b3=true which should be b3==true.

Upvotes: 3

Blue Boy
Blue Boy

Reputation: 610

Try this:

public boolean anyonePrime(int num1, int num2, int num3)
{    
   return (checkPrime(num1) || checkPrime(num2) || checkPrime(num3))
}    
    public boolean checkPrime(int num)
    {
     boolean b0=true;
     if(num==1)
     b0=false;
     else
     {
      for(int i=2; i<=num/2; i++)
      { 
        if(num % i == 0)
        { 
            b0=false;
        }

      }
     } 
       if(b0==true)
       return true;
       else 
       return false;
    //write your code here

    }   
}

I just removed the 'b0 = true line' and tidied up some code

Upvotes: 2

Nathaniel Jones
Nathaniel Jones

Reputation: 1849

You appear to have a typo in your code. You set b0=true; before checking if(b0==true);, so it will always return true. The simple thing to do would simply be to return false as soon as any check finds it is not prime, rather than setting b0 to false and then continuing to do more work.

Upvotes: 3

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