Add tests, remove main in SquareRootBinarySearch (#5676)

Author: Hardvan

DIRECTORY.md

@@ -1016,6 +1016,7 @@
             * [RecursiveBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RecursiveBinarySearchTest.java)
             * [RowColumnWiseSorted2dArrayBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/RowColumnWiseSorted2dArrayBinarySearchTest.java)
             * [SortOrderAgnosticBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/SortOrderAgnosticBinarySearchTest.java)
+            * [SquareRootBinarySearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/SquareRootBinarySearchTest.java)
             * [TestSearchInARowAndColWiseSortedMatrix](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/searches/TestSearchInARowAndColWiseSortedMatrix.java)
           * sorts
             * [BeadSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BeadSortTest.java)

src/main/java/com/thealgorithms/searches/SquareRootBinarySearch.java

@@ -1,7 +1,5 @@
 package com.thealgorithms.searches;
 
-import java.util.Scanner;
-
 /**
  * Given an integer x, find the square root of x. If x is not a perfect square,
  * then return floor(√x).
@@ -18,20 +16,6 @@ public final class SquareRootBinarySearch {
     private SquareRootBinarySearch() {
     }
 
-    /**
-     * This is the driver method.
-     *
-     * @param args Command line arguments
-     */
-    public static void main(String[] args) {
-        Scanner sc = new Scanner(System.in);
-        System.out.print("Enter a number you want to calculate square root of : ");
-        int num = sc.nextInt();
-        long ans = squareRoot(num);
-        System.out.println("The square root is : " + ans);
-        sc.close();
-    }
-
     /**
      * This function calculates the floor of square root of a number. We use
      * Binary Search algorithm to calculate the square root in a more optimised
@@ -40,7 +24,7 @@ public static void main(String[] args) {
      * @param num Number
      * @return answer
      */
-    private static long squareRoot(long num) {
+    static long squareRoot(long num) {
         if (num == 0 || num == 1) {
             return num;
         }

src/test/java/com/thealgorithms/searches/SquareRootBinarySearchTest.java

@@ -0,0 +1,57 @@
+package com.thealgorithms.searches;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class SquareRootBinarySearchTest {
+
+    @Test
+    void testPerfectSquare() {
+        long input = 16;
+        long expected = 4;
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of 16 should be 4");
+    }
+
+    @Test
+    void testNonPerfectSquare() {
+        long input = 15;
+        long expected = 3;
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of 15 should be 3");
+    }
+
+    @Test
+    void testZero() {
+        long input = 0;
+        long expected = 0;
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of 0 should be 0");
+    }
+
+    @Test
+    void testOne() {
+        long input = 1;
+        long expected = 1;
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of 1 should be 1");
+    }
+
+    @Test
+    void testLargeNumberPerfectSquare() {
+        long input = 1000000;
+        long expected = 1000;
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of 1000000 should be 1000");
+    }
+
+    @Test
+    void testLargeNumberNonPerfectSquare() {
+        long input = 999999;
+        long expected = 999;
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of 999999 should be 999");
+    }
+
+    @Test
+    void testNegativeInput() {
+        long input = -4;
+        long expected = 0; // Assuming the implementation should return 0 for negative input
+        assertEquals(expected, SquareRootBinarySearch.squareRoot(input), "Square root of negative number should return 0");
+    }
+}