Morse Decoder program keep giving unwanted [ instead of English. Why?

Question

I was trying to decode morse code as an assignment, but I somehow am stuck on how this output is always [ instead of the English wordings.

Here are some of the test cases:

Test 1

• Input: ._.|.._|_.

• Output: RUN

Test 2

• Input: _|....|..|...||..|...||_|....|.||.__|._|_.__

• Output: THIS IS THE WAY

Test 3

• Input: ...|....|._|_.|_|._|._.|._|__

• Output: SHANTARAM

Test 4

• Input: .__.|.|___|.__.|._..|.||..|_.||_|....|.|..|._.||._.|..|__.|....|_||__|..|_.|_..|...||_.|.|..._|.|._.||_|._|_._|.||.__.|._.|..|_..|.||..|_.||_|....|.|..|._.||_|._|._..|.|_.|_|...

• Output: PEOPLE IN THEIR RIGHT MINDS NEVER TAKE PRIDE IN THEIR TALENTS

Below is my code.

#include <iostream>
#include <string>
#include <sstream>

/**
 * A morse code decoder.
 */

using namespace std;

// IMPORTANT:  Do NOT change any of the function headers
//             It means that you will need to use the function headers as is
//             You may add other functions wherever appropriate

/**
 * Decode the morse code `s` and return the text character
 */
string morseCodeToText(string s)
{
    string text = "";
    string currentLetter = "";

    string const morsecode[] = {".-", "-...", "-.-.", "-..", ".", "..-.",                  //array of alphabet equivalent morse codes
    "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-",
    ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."};

    istringstream ss(s);

    size_t const characters = 26;

    while(ss >> currentLetter)
    {
        size_t index = 0;
        while(currentLetter != morsecode[index] && index < characters)
        {
            ++index;                         //increment here so we don't have to decrement after the loop like if we put in the condition
        }

        text += 'A' + index;
    }

    return text;
}


int main()
{
    string s;
    cin >> s;
    cout << morseCodeToText(s) << '\n';

    return 0;
}

Answer 1

while(ss >> currentLetter)

Here you're reading your input until a newline is found. You want to read until a | is meet.

For that, you can simply rely on std::getline() (see delim):

while(std::getline(ss, currentLetter, '|'))

---

Why [ though?

currentLetter != morsecode[index]

You're comparison is always false. This makes index be 26 when the inner while loop ends. This leads to:

text += 'A' + index; // 65 + 26 = 91 '['

test being always one-past-Z, which is [ in ASCII.