60 lines
1.7 KiB
Java
60 lines
1.7 KiB
Java
package Searches;
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import java.util.Scanner;
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/**
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* Given an integer x, find the square root of x. If x is not a perfect square, then return floor(√x).
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* <p>
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* For example,
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* if x = 5, The answer should be 2 which is the floor value of √5.
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* <p>
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* The approach that will be used for solving the above problem is not going to be a straight forward Math.sqrt().
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* Instead we will be using Binary Search to find the square root of a number in the most optimised way.
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*
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* @author sahil
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*/
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public class SquareRootBinarySearch {
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/**
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* This is the driver method.
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*
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* @param args Command line arguments
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*/
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public static void main(String args[]) {
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Scanner sc = new Scanner(System.in);
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System.out.print("Enter a number you want to calculate square root of : ");
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int num = sc.nextInt();
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long ans = squareRoot(num);
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System.out.println("The square root is : " + ans);
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}
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/**
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* This function calculates the floor of square root of a number.
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* We use Binary Search algorithm to calculate the square root
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* in a more optimised way.
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*
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* @param num Number
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* @return answer
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*/
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private static long squareRoot(long num) {
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if (num == 0 || num == 1) {
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return num;
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}
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long l = 1;
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long r = num;
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long ans = 0;
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while (l <= r) {
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long mid = l + (r - l) / 2;
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if (mid == num / mid)
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return mid;
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else if (mid < num / mid) {
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ans = mid;
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l = mid + 1;
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} else {
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r = mid - 1;
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}
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}
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return ans;
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}
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}
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