« Replace pi recursively in a string

Problem

Given a string, compute recursively a new string where all appearances of "pi" have been replaced by "3.14".

Constraints :

1 <= |S| <= 50 where |S| represents the length of string S.

Sample Input 1 :

xpix

Sample Output 1 :

x3.14x

Sample Input 2 :

pipi

Sample Output 2 :

3.143.14

Sample Input 3 :

pip

Sample Output 3:

3.14p

Constraints:-

1<=|S|<=50

Solution

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1#include <iostream>
2#include <iomanip>
3#include <algorithm>
4#include <string>
5#include <cstring>
6#include <vector>
7#include <cmath>
8#include <map>
9#include <climits>
10// climits for INT_MIN
11#include <unordered_map>
12using namespace std;
13
14void replacePi(char input[])
15{
16    if (input[0] == '\0' || input[1] == '\0')
17    {
18        return;
19    }
20
21    replacePi(input + 1);
22
23    if (input[0] == 'p' && input[1] == 'i')
24    {
25        int length = 0;
26        while (input[length] != '\0')
27        {
28            length++;
29        }
30        for (int i = length; i >= 2; i--)
31        {
32            input[i + 2] = input[i];
33        }
34        length = length + 2;
35
36        input[0] = '3';
37        input[1] = '.';
38        input[2] = '1';
39        input[3] = '4';
40    }
41}
42
43int main()
44{
45    char input[10000];
46    cin.getline(input, 10000);
47    replacePi(input);
48    cout << input << endl;
49    return 0;
50}