Replace Character Recursively #

Given an input string S and two characters c1 and c2, you need to replace every occurrence of character c1 with character c2 in the given string.

Do this recursively.

Input Format :
Line 1 : Input String S
Line 2 : Character c1 and c2 (separated by space)
Output Format :
Updated string
Constraints :
1 <= Length of String S <= 10^6

Sample Input 1

abacd
a x

Sample Output 1

xbxcd
Code 
void replaceCharacter(char input[], char c1, char c2)
{
    // static char* write = input;
    if(*input==0)
        return;
    if(*input==c1)
        *input=c2;
    replaceCharacter(input+1, c1, c2);
}

Remove Duplicates Recursively #

Given a string S, remove consecutive duplicates from it recursively.

Input Format :
String S
Output Format :
Output string
Constraints :
1 <= Length of String S <= 10^3

Sample Input

aabccba

Sample Output

abcba
Code 
void helper(char* input, char* write);
void removeConsecutiveDuplicates(char *input)
{
    if(*input==0)
        return;
    helper(input, input);
}

void helper(char* curr, char* write)
{
    if(*curr==0)
        return;

    // search for the difference
    while(*curr==*write)
        curr++;
    // curr is now a different aspect
    if(*curr=='\0')
    {
        *(write+1)=0;
        return;
    }

    *(write+1) = *curr;
    // call the function
    helper(curr, write+1);
}

Merge Sort #

Given a string S, remove consecutive duplicates from it recursively.

Input Format :
String S
Output Format :
Output string
Constraints :
1 <= Length of String S <= 10^3

Sample Input

aabccba

Sample Output

abcba
Code 
void helper(char* input, char* write);
void removeConsecutiveDuplicates(char *input)
{
    if(*input==0)
        return;
    helper(input, input);
}

void helper(char* curr, char* write)
{
    if(*curr==0)
        return;

    // search for the difference
    while(*curr==*write)
        curr++;
    // curr is now a different aspect
    if(*curr=='\0')
    {
        *(write+1)=0;
        return;
    }

    *(write+1) = *curr;
    // call the function
    helper(curr, write+1);
}