Take as input str, a string. Assume that value of a=1, b=2, c=3, d=4, …. z=26. Write a recursive function (return type Arraylist) to print all possible codes for the string. E.g. for “1123” possible codes are aabc, kbc, alc, aaw, kw. Input Format Enter a number Constraints None Output Format Display all the possible codes Sample Input 1125 Sample Output [aabe, aay, ale, kbe, ky] in c+++ withought vector use

Here's a possible implementation of the recursive function in C++ without using vectors:

cppCopy code

#include <iostream> #include <string> using namespace std; void printCodes(string input, string output) { if (input.length() == 0) { cout << output << endl; return; } // consider single digit as a code int digit = input[0] - '0'; char ch = 'a' + digit - 1; printCodes(input.substr(1), output + ch); // consider two digits as a code if (input.length() >= 2) { int digits = stoi(input.substr(0, 2)); if (digits >= 10 && digits <= 26) { ch = 'a' + digits - 1; printCodes(input.substr(2), output + ch); } } } int main() { string input; cin >> input; printCodes(input, ""); return 0; }

In this implementation, the printCodes function takes two parameters: the input string and the current output string (which starts as an empty string). The function first checks if the input string is empty, in which case it prints the current output string and returns. Otherwise, it considers the first digit of the input string and adds the corresponding character code to the output string. Then, it recursively calls itself with the remaining part of the input string and the updated output string. Finally, if the input string has at least two digits and the first two digits form a valid code, the function considers the two digits together and recursively calls itself with the remaining part of the input string and the updated output string.

The main function simply reads the input string and calls the printCodes function with the input string and an empty output string.

DFA stands for :

In C, string constants are enclosed in a pair of.......................