Recursively remove all adjacent duplicates

In this blog we are discussing a problem asked by paytm, samsung. Problem: Given a strings, recursively remove adjacent duplicate characters from the string s. The output string should not have any adjacent duplicates. Input: The first line of input contains a string str. Output: Print a new line containing the resulting string. Constraints: 1 <= Length of string <= 50 Example: Input 1: programmersdoor Output 1: prograersdr Input 2: abccabbdadd Output: abada Implementation Using C++: #include <iostream>
#include <string.h>
using namespace std;

// removes all adjacent duplicates from
char* removeAdjacentDuplicate(char* str, int n)
// k maintains the index of next free location in the result
// and i maintains the current index in the string
int i, k = 0;
int len = strlen(str);

// start from second character
for (i = 1; i < len; i++)
// if current char is not same as the
// previous char, add it to result
if (str[i - 1] != str[i])
str[k++] = str[i - 1];
// remove adjacent duplicates
while (i < len && str[i - 1] == str[i])

// Add last character to result
str[k++] = str[i - 1];

// null terminate the string
str[k] = '\0';

if (k != n)
return removeAdjacentDuplicate(str, k);

return str;

int main()
char str[] = "programmersdoor";
int n = strlen(str);

cout <<removeAdjacentDuplicate(str, n);

return 0;
} Happy Coding! Follow us on Instagram @programmersdoor Join us on Telegram @programmersdoor Please write comments if you find any bug in above code/algorithm, or find other ways to solve the same problem. Follow Programmers Door for more. #blog #interview #placement #string #manipulation #paytm #samsung

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