Question

Using ONLY the following header functions:

#include <iostream>
#include <string>
#include <cassert>
#include <vector>
using namespace std;

Create a C++ function that satisfies the condition using recursion, NO WHILE OR FOR LOOPS.

Pre-condition:
    s.size() == t.size()
Post-condition:
    Returns a vector where the first string is the first character of s followed by the first character of t, the second string is the second character of s followed by the second character of t, and so on.
    For example, zip("abc", "xyz") returns {"ax", "by", "cz"}.

These are the function names:

vector zip(const string& s, const string& t);
void zip_test();

The test function should automatically run when called from main as such:

int main() {

void zip_test();

return 0;

}

!!! No FOR or WHILE Loops Allowed, Not Even the Testing Function !!! Should be done using recursion

Answer 1

// do comment if any problem arises

// code]Using ONLY the following header functions:

#include <iostream>

#include <string>

#include <cassert>

#include <vector>

using namespace std;

// Pre - condition : s.size() == t.size()

// Post - condition : Returns a vector where the first string is the

// first character of s followed by the first character of t,

// the second string is the second character of s followed

// by the second character of t, and so on.

vector<string> zip(const string &s, const string &t)

{

    static int i = 0;

    if (i == s.size())

    {

        i = 0;

        return (vector<string>){};

    }

    // create s[i]+t[i]

    string temp = "";

    temp = s[i];

    temp += t[i];

    i++;

    // recursive call

    vector<string> temp1 = zip(s, t);

    // add temp to vector

    vector<string> temp2;

    temp2.push_back(temp);

    // add temp1 to temp2 vector

    temp2.insert(temp2.end(), temp1.begin(), temp1.end());

    // return temp2

    return temp2;

}

// For example, zip("abc", "xyz")

// returns{"ax", "by", "cz"}.

void zip_test()

{

    // call zip for testing

    vector<string> testing = zip("abc", "xyz");

    vector<string> output = {"ax",

                             "by",

                             "cz"};

    // testing output

    if (testing == output)

        cout << "Correct\n";

    else

        cout << "Incorrect";

}

int main()

{

    zip_test();

    return 0;

}

Output: