Removing consecutive duplicates - 2

Problem Statement - link #

You are given string str. You need to remove the pair of duplicates. Note: The pair should be of adjacent elements and after removing a pair the remaining string is joined together.

Your Task: This is a function problem. You only need to complete the function removePair() that takes a string as a parameter and returns the modified string. Return an empty string if the whole string is deleted.

Expected Time Complexity: O(N) Expected Auxiliary Space: O(N)

Examples #

Example 1:

Input:
aaabbaaccd

Output: 
ad

Explanation: 
Remove (aa)abbaaccd =>abbaaccd
Remove a(bb)aaccd => aaaccd
Remove (aa)accd => accd
Remove a(cc)d => ad

Example 2:

Input: 
aaaa

Output: 
Empty String

Explanation: 
Remove (aa)aa => aa
Again removing pair of duplicates then (aa) 
will be removed and we will get 'Empty String'.

Constraints #

• 1 <= |str| <= 1000

Solutions #

class Solution
{
    public:
    //Function to remove pair of duplicates from given string using Stack.
    string removePair(string str)
    {
        // Your code here
        stack<char> s;
        for(char c: str){
            if(!s.empty() && s.top()==c){
                s.pop();
                continue;
            }
            s.push(c);
        }
        string res = "";
        while(!s.empty()) {
            res = s.top() + res;
            s.pop();
        }
        return res;
        
    }
};