duplicates in array : comments added

Author: Ram swaroop

src/me/ramswaroop/arrays/DuplicatesInArray.java

@@ -12,11 +12,19 @@
 public class DuplicatesInArray {
 
     /**
+     * Given an array of n elements which contains elements from 0 to n-1, with any of
+     * these numbers appearing any number of times. Find these repeating numbers in O(n)
+     * and using only constant memory space.
+     * <p/>
+     * For example, let n be 7 and array be {1, 2, 3, 1, 3, 6, 6}, the answer should be
+     * 1, 3 and 6.
+     * <p/>
+     * EXPLANATION:
      * The algorithm is simple. We use index of the array to track repeating elements.
-     * Once we encounter a element lets say 2 then we make the 2nd index -ve just to mark
-     * that we have encountered 2. When we encounter 2 again and see that 2nd index
+     * Once we encounter a element lets say 2 then we make the element in 2nd index -ve just
+     * to mark that we have encountered 2. When we encounter 2 again and see that 2nd index
      * is already -ve we conclude that 2 is repeated.
-     * 
+     * <p/>
      * Similar to {@link me.ramswaroop.arrays.TwoRepeatingElements#findTwoRepeatingElements(int[])}.
      *
      * @param a

src/me/ramswaroop/arrays/TwoRepeatingElements.java

@@ -64,8 +64,8 @@ public static int[] getTwoRepeatingElements(int[] a) {
 
     /**
      * The algorithm is simple. We use index of the array to track repeating elements.
-     * Once we encounter a element lets say 2 then we make the 2nd index -ve just to mark
-     * that we have encountered 2. When we encounter 2 again and see that 2nd index
+     * Once we encounter a element lets say 2 then we make the element in 2nd index -ve just
+     * to mark that we have encountered 2. When we encounter 2 again and see that 2nd index
      * is already -ve we conclude that 2 is repeated.
      * 
      * Similar to {@link me.ramswaroop.arrays.DuplicatesInArray#findDuplicatesInArray(int[])}.