Remove All Adjacent Duplicates in String LeetCode (Adjacent Character Remove)

Given a string, complete the given function to recursively remove the adjacent duplicate characters and return the resultant string. If there are no characters left in the resultant string, return "-1" (without quotes). 

Example 1

• Input: ABCCBCBA 

• Output: ACBA 

• Explanation: (ABCCBCBA --> ABBCBA --> ACBA) 

Example 2

• Input: AA 

• Output: -1 

 Solution 1:

1.  Use two pointers p1 pointing to first char and p2 to the second char

1.  Repeat the following till p2 reaches the end or the length of string is zero

1.  if char[p1]==char[p2], update the string by removing these chars, re-assign p1 to 0 and p2 to 1

1.  if (a) is false advance p1 and p2

 Complexity: O(n)
This is an interesting problem that is well discussed in LeetCode and GeeksForGeeks A collection of hundreds of interview questions and solutions are available in our blog at Interview Question

Solution