Question

In Java, Write a program without using a build in square-root operator to compute square-root of a number that is known to have an integer square root

Answer 1

package math;

public class FindSquireRoot {

public static int findSquireRoot(int n){

int l=1,s=n; //start from 1 to upto that no

if(n==0 || n==1) //if n is zero or 1 return same no

return n;

while(l<=s){ //Iterate through both crosses

int mid=(l+s)/2; //calculate mid

if(mid*mid==n) //if mid*mid==n this is root

return mid;

else if(mid*mid>n){ //mid*mid>n decrement to mid -1

s=mid-1;

}

else{ //mid*mid<n increment to mid +1

l=mid+1;

}

}

return -1;

}

//driver program to test

public static void main(String[] args) {

System.out.println(findSquireRoot(225));

System.out.println(findSquireRoot(81));

System.out.println(findSquireRoot(9));

}

}

output

15

9

3