# Remove all occurrences of a character in a string | Recursive approach

Given string str, the task is to write a recursive program to remove all the occurrences of a character X in the string.

Examples:

Input: str = “geeksforgeeks”, c = ‘e’
Output: gksforgks

Input: str = “geeksforgeeks”, c = ‘g’
Output: eeksforeeks

Iterative Approach: The iterative approach to this problem can be found in this post.

Recursive Approach: Below are the steps:

1. Get the string str and character X for which character X is to be removed.
2. Recursively iterate for all the character in the string:
• Base Case: If the length of the string str called recursively is 0 then return the empty string from the function.
```if(str.length()==0) {
return "";
}
```
• Recursive Call: If the base case is not met, then check for the character at 0th index if it is X then recursively iterate for the substring removing the first character.
```if (str == X) {
return recursive_function(str.substr(1), X);
}
```
• Return Statement: At each recursive call(except the base case and the above condition), return the recursive function for the next iteration including the character at 0th index.
```return str + recursive_function(str.substr(1), X)
```

Below is the implementation of the above approach:

## C++

 `// C++ program for the above approach ` `#include ` `using` `namespace` `std; ` ` `  `// Function to remove all occurrences ` `// of a character in the string ` `string removeCharRecursive(string str, ` `                           ``char` `X) ` `{ ` `    ``// Base Case ` `    ``if` `(str.length() == 0) { ` `        ``return` `""``; ` `    ``} ` ` `  `    ``// Check the first character ` `    ``// of the given string ` `    ``if` `(str == X) { ` ` `  `        ``// Pass the rest of the string ` `        ``// to recursion Function call ` `        ``return` `removeCharRecursive(str.substr(1), X); ` `    ``} ` ` `  `    ``// Add the first character of str ` `    ``// and string from recursion ` `    ``return` `str ` `           ``+ removeCharRecursive(str.substr(1), X); ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``// Given String ` `    ``string str = ``"geeksforgeeks"``; ` ` `  `    ``// Given character ` `    ``char` `X = ``'e'``; ` ` `  `    ``// Function Call ` `    ``str = removeCharRecursive(str, X); ` `    ``cout << str; ` `    ``return` `0; ` `} `

Output:

```gksforgks
```

Time Complexity: O(N), where N is the length of the string
Auxiliary Space: O(1) My Personal Notes arrow_drop_up