print_all_codes.cpp

/*
Q-->Print all Codes - String
Assume that the value of a = 1, b = 2, c = 3, ... , z = 26. You are given a numeric string S. Write a program to print the list of all possible codes that can be generated from the given string.
Note : The order of codes are not important. Just print them in different lines.
Input format :
A numeric string S
Output Format :
All possible codes in different lines
Constraints :
1 <= Length of String S <= 10
Sample Input:
1123
Sample Output:
aabc
kbc
alc
aaw
kw
*/

#include <string>
using namespace std;
void printAllPossibleCodesHelper(string input, string output){ 
    if(input[0] == '\0'){
        cout << output << endl;
        return; 
        
    } 
    
    int num = input[0] - 48; 
    char ch = num - 1 + 'a';
    printAllPossibleCodesHelper(input.substr(1), output + ch);
    if(input[1] != '\0'){ 
        num = num * 10 + input[1] - 48;
        ch = num - 1 + 'a';
        if(num >= 10 && num <= 26){
            printAllPossibleCodesHelper(input.substr(2), output + ch);
        }
    }
}
            
void printAllPossibleCodes(string input) {
    printAllPossibleCodesHelper(input, "");
}