new algorithms & add author

Author: melmedany

src/main/java/DavisStaircase.java

@@ -0,0 +1,40 @@
+
+/**
+ * @author medany
+ */
+
+/*
+ * Davis has s staircases in his house and he likes to climb each staircase 1,
+ * 2, or 3 steps at a time. Being a very precocious child, he wonders how many
+ * ways there are to reach the top of the staircase.
+ * 
+ * Given the respective heights for each of the s staircases in his house, find
+ * and print the number of ways he can climb each staircase on a new line.
+ */
+
+public class DavisStaircase {
+
+	public int solve(int num) {
+		switch (num) {
+		case 0:
+		case 1:
+			return 1;
+		default:
+			if (num < 0)
+				return 0;
+
+			int[] waysArr = new int[num];
+
+			waysArr[0] = 1;
+			waysArr[1] = 2;
+			waysArr[2] = 4;
+
+			for (int i = 3; i < num; i++) {
+				waysArr[i] = waysArr[i - 1] + waysArr[i - 2] + waysArr[i - 3];
+			}
+			int ways = waysArr[waysArr.length - 1];
+			waysArr = null;
+			return ways;
+		}
+	}
+}

src/main/java/FibonacciNumbers.java

@@ -1,3 +1,8 @@
+
+/**
+ * @author medany
+ */
+
 import java.math.BigInteger;
 
 /**

src/main/java/LinkedListsDetectCycle.java

@@ -1,4 +1,7 @@
 
+/**
+ * @author medany
+ */
 
 import java.util.ArrayList;
 import java.util.List;

src/main/java/LonelyInteger.java

@@ -0,0 +1,15 @@
+
+/**
+ * @author medany
+ */
+
+public class LonelyInteger {
+
+	public int solve(int[] array) {
+		int num = 0;
+		for (int i : array) {
+			num = num ^ i;
+		}
+		return num;
+	}
+}

src/main/java/Node.java

@@ -1,4 +1,7 @@
 
+/**
+ * @author medany
+ */
 
 public class Node {
 	int data;

src/main/java/Primality.java

@@ -0,0 +1,27 @@
+
+/**
+ * @author medany
+ */
+
+public class Primality {
+
+	public boolean solve(int number) {
+		switch ("" + number) {
+		case "0":
+		case "1":
+			return false;
+		case "2":
+		case "3":
+			return true;
+		default:
+			if (number % 2 == 0)
+				return false;
+			int sqrt = (int) (Math.sqrt(number) + 1);
+			for (int i = 3; i < sqrt; i += 2) {
+				if (number % i == 0)
+					return true;
+			}
+		}
+		return false;
+	}
+}

test/main/java/DavisStaircaseTest.java

@@ -0,0 +1,29 @@
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author medany
+ */
+
+public class DavisStaircaseTest {
+
+	@Test
+	public void Test_1() {
+
+		DavisStaircase alg = new DavisStaircase();
+
+		int actual = alg.solve(1), expected = 1;
+
+		Assert.assertEquals(expected, actual);
+	}
+
+	@Test
+	public void Test_2() {
+
+		DavisStaircase alg = new DavisStaircase();
+
+		int actual = alg.solve(7), expected = 44;
+
+		Assert.assertEquals(expected, actual);
+	}
+}

test/main/java/FibonacciNumbersTest.java

@@ -1,7 +1,7 @@
-import static org.junit.Assert.assertEquals;
 
 import java.math.BigInteger;
 
+import org.junit.Assert;
 import org.junit.Test;
 
 /**
@@ -17,7 +17,7 @@ public void Test_1() {
 		BigInteger actual = alg.solve(1), expected = BigInteger.ONE;
 
 		System.out.println(actual);
-		assertEquals(expected, actual);
+		Assert.assertEquals(expected, actual);
 	}
 
 	@Test
@@ -27,7 +27,7 @@ public void Test_2() {
 		BigInteger actual = alg.solve(5), expected = BigInteger.valueOf(5);
 
 		System.out.println(actual);
-		assertEquals(expected, actual);
+		Assert.assertEquals(expected, actual);
 	}
 
 	@Test
@@ -37,7 +37,7 @@ public void Test_3() {
 		BigInteger actual = alg.solve(10), expected = BigInteger.valueOf(55);
 
 		System.out.println(actual);
-		assertEquals(expected, actual);
+		Assert.assertEquals(expected, actual);
 	}
 
 	@Test
@@ -49,6 +49,6 @@ public void Test_4() {
 				"43466557686937456435688527675040625802564660517371780402481729089536555417949051890403879840079255169295922593080322634775209689623239873322471161642996440906533187938298969649928516003704476137795166849228875");
 
 		System.out.println(actual);
-		assertEquals(expected, actual);
+		Assert.assertEquals(expected, actual);
 	}
 }

test/main/java/LonelyIntegerTest.java

@@ -0,0 +1,56 @@
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author medany
+ */
+
+public class LonelyIntegerTest {
+
+	@Test
+	public void Test_1() {
+
+		LonelyInteger alg = new LonelyInteger();
+
+		int actual = alg.solve(new int[] { 1, 1, 2 }), expected = 2;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+
+	@Test
+	public void Test_2() {
+
+		LonelyInteger alg = new LonelyInteger();
+
+		int actual = alg.solve(new int[] { 0, 0, 1, 2, 1 }), expected = 2;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+
+	@Test
+	public void Test_3() {
+
+		LonelyInteger alg = new LonelyInteger();
+
+		int actual = alg.solve(new int[] { 4, 9, 95, 93, 57, 4, 57, 93, 9 }), expected = 95;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+
+	@Test
+	public void Test_4() {
+
+		LonelyInteger alg = new LonelyInteger();
+
+		int actual = alg.solve(new int[] { 59, 88, 14, 8, 85, 1, 94, 74, 57, 96, 39, 2, 47, 43, 35, 17, 53, 52, 92, 31,
+				99, 48, 94, 30, 92, 60, 32, 45, 88, 13, 39, 50, 22, 65, 89, 46, 65, 76, 57, 67, 99, 35, 76, 46, 85, 82,
+				45, 62, 53, 80, 74, 22, 31, 52, 82, 13, 41, 96, 2, 1, 80, 62, 4, 20, 50, 89, 59, 67, 60, 8, 41, 14, 47,
+				48, 17, 4, 43, 30, 32 }), expected = 20;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+}

test/main/java/PrimalityTest.java

@@ -0,0 +1,53 @@
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author medany
+ */
+
+public class PrimalityTest {
+
+	@Test
+	public void Test_1() {
+
+		Primality alg = new Primality();
+
+		boolean actual = alg.solve(10), expected = false;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+
+	@Test
+	public void Test_2() {
+
+		Primality alg = new Primality();
+
+		boolean actual = alg.solve(27), expected = true;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+
+	@Test
+	public void Test_3() {
+
+		Primality alg = new Primality();
+
+		boolean actual = alg.solve(99), expected = true;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+
+	@Test
+	public void Test_4() {
+
+		Primality alg = new Primality();
+
+		boolean actual = alg.solve(250), expected = false;
+
+		Assert.assertEquals(expected, actual);
+
+	}
+}