Removing consecutive duplicates

Problem Statement - link #

You are given string str. You need to remove the consecutive duplicates from the given string using a Stack.

Your Task: This is a function problem. You need to complete the function removeConsecutiveDuplicates() that takes a string as a parameter and returns the modified string. The printing is done automatically by the driver code.

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

Examples #

Example 1:

Input: 
aaaaaabaabccccccc

Output: 
ababc

Explanation: 
Removing all consecutive duplicates, 
we have no duplicates consecutively.

Example 2:

Input: 
abbccbcd

Output: 
abcbcd

Explanation: 
Removing all the consecutive duplicates, 
we have the output as abcbcd.

Constraints #

• 1 <= |str| <= 1000

Solutions #

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