CC-14 : Find Square root of a number.

Description:

Given an input number find its square root. If the input number is not a perfect square, then its square root will be a decimal number. In case of decimal square root, just return the integer part of square root.

Test cases and expected outputs:

Input Parameters	Expected outputs
Num=144	Square root of 144 is 12
Num=16	Square root of 16 is 4
Num=12	Square root of 12 is 3

Pseudocode:

findSqrt(num):

Integer named num is received as input parameter.

Set integer variable firstNum to zero, we will use this variable to store the first number above which we will search for square root of num.

Set integer variable lastNum to nums, we will use this variable to store the last number below which we will search for square root of num.

Set integer variable sqrt to 1.

While (firstNum <= lastNum) do the following steps:

Set integer variable mid to (lastNum-firstNum)/2.

Set integer variable midNum to (firstNum)to get mid number of current range.

If (midNum*midNum<=nums ):

Set sqrt=midNum.

Set firstNum=midNum+1.

Else if (midNum*midNum > nums ) then:

lastNum=midNum-1.

Return sqrt as it contains the square root of num.

Code:

public int findSqrt(int num){
	int firstNum=1;
	int lastNum=num;
	int sqrt=1;
	while (firstNum <= lastNum) {
		int mid=(lastNum-firstNum)/2;
		int midNum=firstNum+mid;
		if (midNum*midNum<=num) {
			sqrt=midNum;	
			firstNum=midNum+1;
		} else { if (midNum*midNum > num) {
			lastNum=midNum-1;
		}
		}		
	}	
	return sqrt;
}

Click here to download and run code and test cases !

Below fully running code can be copied and run on Eclipse or other Java IDEs. Refer the classname in code below. If the class name below is "A", save the code below to a file named A.java before running it. Be sure to try your own test cases to enhance your understanding ! You can also tweak the code to optimize or add enhancements and custom features.

public class SearchFindSqrt {

public int findSqrt(int num){
	int firstNum=1;
	int lastNum=num;
	int sqrt=1;
	while (firstNum <= lastNum) {
		int mid=(lastNum-firstNum)/2;
		int midNum=firstNum+mid;
		if (midNum*midNum<=num) {
			sqrt=midNum;	
			firstNum=midNum+1;
		} else { if (midNum*midNum > num) {
			lastNum=midNum-1;
		}
		}		
	}	
	return sqrt;
}

public static void main(String[] args) {
	/***********************
	 Test cases given below:
	 **********************/
	int retVal;
	try {
	
	SearchFindSqrt search=new SearchFindSqrt();
	int findRt=144;
	retVal=search.findSqrt(findRt);
	System.out.println("\nSquare root of "+findRt + " is "+ retVal);	
	
	findRt=16;
	retVal=search.findSqrt(findRt);
	System.out.println("\nSquare root of "+findRt + " is "+ retVal);	
	
	findRt=12;
	retVal=search.findSqrt(findRt);
	System.out.println("\nSquare root of "+findRt + " is "+ retVal);	
	
	}catch (Exception exception) {
		System.out.print("Exception: "+ exception);
		exception.printStackTrace();
	}
		
}

}