Fixed some typos and links for javadoc, and some refactoring (#4755)

src/main/java/com/thealgorithms/ciphers/AESEncryption.java

@@ -19,7 +19,7 @@ public class AESEncryption {
 
     /**
      * 1. Generate a plain text for encryption 2. Get a secret key (printed in
-     * hexadecimal form). In actual use this must by encrypted and kept safe.
+     * hexadecimal form). In actual use this must be encrypted and kept safe.
      * The same key is required for decryption.
      */
     public static void main(String[] args) throws Exception {

src/main/java/com/thealgorithms/conversions/AnyBaseToDecimal.java

@@ -1,7 +1,7 @@
 package com.thealgorithms.conversions;
 
 /**
- * @author Varun Upadhyay (https://github.com/varunu28)
+ * @author Varun Upadhyay (<a href="https://github.com/varunu28">...</a>)
  */
 // Driver program
 public class AnyBaseToDecimal {

src/main/java/com/thealgorithms/conversions/DecimalToAnyBase.java

@@ -5,7 +5,7 @@ import java.io.InputStreamReader;
 import java.util.ArrayList;
 
 /**
- * @author Varun Upadhyay (https://github.com/varunu28)
+ * @author Varun Upadhyay (<a href="https://github.com/varunu28">...</a>)
  */
 // Driver Program
 public class DecimalToAnyBase {

src/main/java/com/thealgorithms/conversions/RgbHsvConversion.java

@@ -10,8 +10,8 @@ import java.util.Arrays;
  * models how colors appear under light. In it, colors are represented using
  * three components: hue, saturation and (brightness-)value. This class provides
  * methods for converting colors from one representation to the other.
- * (description adapted from https://en.wikipedia.org/wiki/RGB_color_model and
- * https://en.wikipedia.org/wiki/HSL_and_HSV).
+ * (description adapted from <a href="https://en.wikipedia.org/wiki/RGB_color_model">[1]</a> and
+ * <a href="https://en.wikipedia.org/wiki/HSL_and_HSV">[2]</a>).
  */
 public class RgbHsvConversion {
 

src/main/java/com/thealgorithms/geometry/GrahamScan.java

@@ -6,7 +6,7 @@ import java.util.Stack;
 
 /*
  * A Java program that computes the convex hull using the Graham Scan algorithm
- * In the best case, time complexity is O(n), while in the worst case, it is log(n).
+ * In the best case, time complexity is O(n), while in the worst case, it is O(nlog(n)).
  * O(n) space complexity
  *
  * This algorithm is only applicable to integral coordinates.
@@ -106,16 +106,14 @@ public class GrahamScan {
 
         /**
          * @param p2 Co-ordinate of point to compare to.
-         * This function will compare the points and will return a positive integer it the
+         * This function will compare the points and will return a positive integer if the
          * point is greater than the argument point and a negative integer if the point is
          * less than the argument point.
          */
         public int compareTo(Point p2) {
-            if (this.y < p2.y) return -1;
-            if (this.y > p2.y) return +1;
-            if (this.x < p2.x) return -1;
-            if (this.x > p2.x) return +1;
-            return 0;
+            int res = Integer.compare(this.y, p2.y);
+            if (res == 0) res = Integer.compare(this.x, p2.x);
+            return res;
         }
 
         /**