TheAlgorithms · deadshotsb · May 25, 2020 · May 25, 2020 · May 25, 2020 · May 25, 2020
diff --git a/src/main/java/com/conversions/HexadecimalToBinary.java b/src/main/java/com/conversions/HexadecimalToBinary.java
@@ -0,0 +1,106 @@
+package com.conversions;
+
+public class HexadecimalToBinary {
+	 /**
+     * This method converts a hexadecimal number to
+     * a binary number.
+     *
+     * @param hexStr The hexadecimal number
+     * @return The binary number
+     */
+
+	public String hexToBin (String hexStr) {
+
+		String binaryString = "", hexaNumbers = "0123456789ABCDEF", 
+				DecimalStr ="", binaryStringBefore ="" , binaryStringAfter = "";
+		int indexOfHex, decimalNumber = 0, k = 1, n =1, z=1, decimalNumberBefore = 0
+				, decimalNumberAfter = 0;
+		char letter;
+		int binaryArray[] = new int [60];
+		int binaryArrayBefore[] = new int [60];
+		int binaryArrayAfter[] = new int [60];
+
+		hexStr = hexStr.toUpperCase();
+		int pointPosition = hexStr.indexOf(".");
+		/**
+		 * Transform the hexadecimal number to decimal number
+		 */
+		if ( pointPosition == -1) {
+		for ( int i = 0 ;  i < hexStr.length(); i++) {
+				letter = hexStr.charAt(i);
+				indexOfHex = hexaNumbers.indexOf(letter);
+				decimalNumber = 16 * decimalNumber + indexOfHex;
+			}
+		}
+		else {
+			for ( int i = 0 ;  i < pointPosition ; i++) {
+				letter = hexStr.charAt(i);
+				indexOfHex = hexaNumbers.indexOf(letter);
+				decimalNumberBefore = 16 * decimalNumberBefore + indexOfHex;
+			}
+			String decimalNumberBeforeStr = String.valueOf(decimalNumberBefore);
+
+			for ( int i = pointPosition+1 ;  i < hexStr.length() ; i++) {
+				letter = hexStr.charAt(i);
+				indexOfHex = hexaNumbers.indexOf(letter);
+				decimalNumberAfter = 16 * decimalNumberAfter + indexOfHex;
+			}
+
+			String decimalNumberAfterStr = String.valueOf(decimalNumberAfter);
+
+			DecimalStr = decimalNumberBeforeStr + '.' + decimalNumberAfterStr;
+			}
+
+
+
+		int pointPositionDec = DecimalStr.indexOf(".");
+		/**
+		 * Check whether the result contains a floating point or not
+		 */
+		if (pointPositionDec == -1) {
+			while (decimalNumber != 0) {
+				binaryArray[k++] = decimalNumber % 2;
+				decimalNumber = decimalNumber / 2;
+			}	
+
+		}else {
+			/**
+			 * If it contains floating points we need to divide it into two parts before the point and after it
+			 */
+				while (decimalNumberBefore != 0) {
+					binaryArrayBefore[z++] = decimalNumberBefore % 2;
+					decimalNumberBefore = decimalNumberBefore / 2;
+				}	
+				while (decimalNumberAfter != 0) {
+					binaryArrayAfter[n++] = decimalNumberAfter % 2;
+					decimalNumberAfter = decimalNumberAfter / 2;
+				}	
+
+		}
+
+		if(pointPositionDec == -1) {
+			for ( int j = k-1 ; j>0 ; j--) {
+				binaryString = binaryString + binaryArray[j];
+			}	
+		}else {
+			for ( int j = z-1 ; j>0 ; j--) {
+				binaryStringBefore = binaryStringBefore + binaryArrayBefore[j];
+			}	
+
+			for ( int j = n-1 ; j>0 ; j--) {
+				binaryStringAfter = binaryStringAfter + binaryArrayAfter[j];
+			}
+			/**
+			 * Remove the zeroes in the end of the hexadecimal
+			 */
+			binaryStringAfter = binaryStringAfter.replaceAll("0*$", "").replaceAll("\\.$", "");
+
+
+			binaryString = binaryStringBefore + "." + binaryStringAfter;
+		}
+
+		return binaryString;
+
+	}
+
+}
diff --git a/src/main/java/com/conversions/HexadecimalToDecimal.java b/src/main/java/com/conversions/HexadecimalToDecimal.java
@@ -0,0 +1,68 @@
+package com.conversions;
+
+
+public class HexadecimalToDecimal {
+
+	/**
+     * This method converts a Hexadecimal number to a decimal  number
+     *
+     * @param hexadecimalStr
+     * @return decimal number
+     */
+	 public String hexToDecimal(String hexaStr) {
+		 String hexaNumbers = "0123456789ABCDEF";
+		 int m, result = 0, decimalNumberBefore = 0, power = -1;
+		 Double decimalNumberAfter = 0.0;
+		 char letter;
+		 String decimalStr;
+		 hexaStr = hexaStr.toUpperCase();
+		 int pointPosition = hexaStr.indexOf(".");
+		 /**
+		  * Check whether the number contains a float point or not
+		  */
+			if ( pointPosition == -1) {
+				 for (int i = 0 ; i < hexaStr.length() ; i++) {
+					 /**
+					  * Letter will store the hexadecimal number as long as we loop through
+					  * the string
+					  */
+					 letter = hexaStr.charAt(i);
+
+					 /**
+					  * m is the index of the number that we are looping through in the
+					  * hexaNumbers
+					  */
+					 m = hexaNumbers.indexOf(letter);
+					 result = 16*result + m;
+				 }
+				  decimalStr = String.valueOf(result);
+
+			}
+				 else {
+					 for ( int i = 0 ;  i < pointPosition ; i++) {
+						 letter = hexaStr.charAt(i);
+						 m = hexaNumbers.indexOf(letter);
+						 decimalNumberBefore = 16*decimalNumberBefore + m;
+						}
+
+						String decimalNumberBeforeStr = String.valueOf(decimalNumberBefore);
+
+						for ( int i = pointPosition+1 ;  i < hexaStr.length() ; i++) {
+							letter = hexaStr.charAt(i);
+							m = hexaNumbers.indexOf(letter);
+							decimalNumberAfter = (decimalNumberAfter + (Math.pow(16, power))*m);
+							power = power-1;
+						}
+						/**
+						 * Retrieve the decimal part of the result
+						 */
+						String decimalNumberAfterStr = String.valueOf(decimalNumberAfter);
+						int indexOfDecimal = decimalNumberAfterStr.indexOf(".");
+						decimalNumberAfterStr = decimalNumberAfterStr.substring(indexOfDecimal);
+
+						decimalStr = decimalNumberBeforeStr + decimalNumberAfterStr;
+				 }
+
+					 return decimalStr ;
+	    }
+}
diff --git a/src/test/java/com/conversions/HexadecimalToBinaryTest.java b/src/test/java/com/conversions/HexadecimalToBinaryTest.java
@@ -0,0 +1,30 @@
+package com.conversions;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class HexadecimalToBinaryTest {
+
+	@Test
+	void test() {
+		//HexadecimaltTesting
+		HexadecimalToBinary hexadecimalToBinary = new HexadecimalToBinary();
+        Assertions.assertEquals("1011110011101111", hexadecimalToBinary.hexToBin("BCEF"), "Incorrect Conversion");
+        Assertions.assertEquals("10101101010101111001101", hexadecimalToBinary.hexToBin("56ABCD"), "Incorrect Conversion");
+        Assertions.assertEquals("10011101111011010001001", hexadecimalToBinary.hexToBin("4ef689"), "Incorrect Conversion");
+        Assertions.assertEquals("10011101111", hexadecimalToBinary.hexToBin("4EF"), "Incorrect Conversion");
+        Assertions.assertEquals("101010111100110111101111", hexadecimalToBinary.hexToBin("ABCDEF"), "Incorrect Conversion");
+        //It returns -1 if you enter a wrong hexaDecimal
+        Assertions.assertEquals("-1", hexadecimalToBinary.hexToBin("K"), "Incorrect Conversion");
+
+
+        //Hexadecimal with floating point testing 
+        Assertions.assertEquals("101010111100.101111", hexadecimalToBinary.hexToBin("ABC.BC"), "Incorrect Conversion");
+        Assertions.assertEquals("10101101010.101111001101", hexadecimalToBinary.hexToBin("56A.BCD"), "Incorrect Conversion");
+        Assertions.assertEquals("1001110.1111011010001001", hexadecimalToBinary.hexToBin("4e.f689"), "Incorrect Conversion");
+        Assertions.assertEquals("1001110.1111", hexadecimalToBinary.hexToBin("4E.F"), "Incorrect Conversion");
+        Assertions.assertEquals("10101011110011011110.1111", hexadecimalToBinary.hexToBin("ABCDE.F"), "Incorrect Conversion");
+
+	}
+
+}
diff --git a/src/test/java/com/conversions/HexadecimalToDecimalTest.java b/src/test/java/com/conversions/HexadecimalToDecimalTest.java
@@ -0,0 +1,32 @@
+package com.conversions;
+
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class HexadecimalToDecimalTest {
+
+	@Test
+	void testHexadecimalToDecimalTest() {
+
+		HexadecimalToDecimal hexadecimalToDecimal = new HexadecimalToDecimal();
+
+		//HexadecimaltTesting
+        Assertions.assertEquals("171", hexadecimalToDecimal.hexToDecimal("AB"), "Incorrect Conversion");
+        Assertions.assertEquals("5680077", hexadecimalToDecimal.hexToDecimal("56ABCD"), "Incorrect Conversion");
+        Assertions.assertEquals("5174921", hexadecimalToDecimal.hexToDecimal("4ef689"), "Incorrect Conversion");
+        Assertions.assertEquals("1263", hexadecimalToDecimal.hexToDecimal("4EF"), "Incorrect Conversion");
+        Assertions.assertEquals("11259375", hexadecimalToDecimal.hexToDecimal("ABCDEF"), "Incorrect Conversion");
+        //It returns -1 if you enter a wrong hexaDecimal
+        Assertions.assertEquals("-1", hexadecimalToDecimal.hexToDecimal("K"), "Incorrect Conversion");
+
+        //Hexadecimal with floating point testing 
+        Assertions.assertEquals("10.6875", hexadecimalToDecimal.hexToDecimal("A.B"), "Incorrect Conversion");
+        Assertions.assertEquals("1386.737548828125", hexadecimalToDecimal.hexToDecimal("56A.BCD"), "Incorrect Conversion");
+        Assertions.assertEquals("78.9630279541015625", hexadecimalToDecimal.hexToDecimal("4e.f689"), "Incorrect Conversion");
+        Assertions.assertEquals("0.93359375", hexadecimalToDecimal.hexToDecimal(".EF"), "Incorrect Conversion");
+        Assertions.assertEquals("171.8044281005859375", hexadecimalToDecimal.hexToDecimal("AB.CDEF"), "Incorrect Conversion");
+
+	}
+
+}