HreturnAllCodes.cpp

#include <iostream>

using namespace std;
#include <string>
using namespace std;
int getCodes(string input, string output[]) { 
    if(input[0] == '\0'){ 
        output[0] = ""; 
        return 1; 
        
    }
    
    int first = input[0] - 48; 
    char firstChar = first + 'a' - 1;
    char secondChar = '\0';
    string smallOutput1[500];
    string smallOutput2[500]; 
    int size1 = getCodes(input.substr(1), smallOutput1); 
    int size2 = 0;
    if(input[1] != '\0'){ 
        int second = first * 10 + input[1] - 48;
        if(second >= 10 && second <= 26){ 
            secondChar = second + 'a' - 1; 
            size2 = getCodes(input.substr(2), smallOutput2); 
            
        }
    }
    
    int k = 0;
    for(int i = 0; i < size1; i++){
        output[k] = firstChar + smallOutput1[i];
        k++; 
        
    } 
    
    for(int i = 0; i < size2; i++){ 
        output[k] = secondChar + smallOutput2[i]; 
        k++;
    }
    return k;
}
int main(){
    string input;
    cin >> input;

    string output[10000];
    int count = getCodes(input, output);
    for(int i = 0; i < count && i < 10000; i++)
        cout << output[i] << endl;
    return 0;
}