Question

string scriviNumeroMinoreMille(int a)
{
    vector<string> v_zero_to_nineteen(20);
    vector<string> v_twenty_to_ninety(8);

    v_zero_to_nineteen = {"zero", "uno", "due", "tre", "quattro", "cinque", "sei", "sette", "otto", "nove", "dieci", "undici",
                          "dodici", "tredici", "quattordici", "quindici", "sedici", "diciassette", "diciotto", "diciannove"};

    v_twenty_to_ninety = {"venti", "trenta", "quaranta", "cinquanta", "sessanta", "settanta", "ottanta", "novanta"};

    string risultato;

    if(a == 0)
    {
        return risultato = "";
    }
    else if(a < 20 && a > 0)
    {
        return risultato = v_zero_to_nineteen[a];
    }
    else if(a == 20 || a == 30 || a == 40 || a == 50 || a == 60 || a == 70 || a == 80 || a == 90)
    {
        return risultato = v_twenty_to_ninety[(a/10)-2];
    }
    else if(a == 100)
    {
        return risultato = "cento";
    }

    int unita = 0;
    int decine = 0;
    int centinaia = 0;

    if(a > 99)
    {
        centinaia = a/100;
        risultato += (v_zero_to_nineteen[centinaia]);
        risultato += "cento";
    }
    if(a > 19)
    {
        if(a-(centinaia*100)%10 == 0)
        {
            decine = (a-(centinaia*100))/10;
            risultato += (v_twenty_to_ninety[decine-2]);
        }
        else
        {
            decine = (a-(centinaia*100)/10);
            risultato += v_twenty_to_ninety[decine-2];
            unita = (a-(centinaia*100)-(decine*10));
            risultato += v_zero_to_nineteen[unita];
        }
    }
    return risultato;
}

I made this function to check a number from 0 to 999 to convert a number in a string. The result would be for example if the input is 100, the output would be “one hundred” (it’s translated in italian)

I don’t understand why in debugging the arguments inside these two if clauses:

if(a > 99)
{
    centinaia = a/100;
    risultato += (v_zero_to_nineteen[centinaia]);
    risultato += "cento";
}
if(a > 19)
{
    if(a-(centinaia*100)%10 == 0)
    {
        decine = (a-(centinaia*100))/10;
        risultato += (v_twenty_to_ninety[decine-2]);
    }
    else
    {
        decine = (a-(centinaia*100)/10);
        risultato += v_twenty_to_ninety[decine-2];
        unita = (a-(centinaia*100)-(decine*10));
        risultato += v_zero_to_nineteen[unita];
    }
}

are not considered in the function. Those two ifs are just skipped. I don’t understand why. If I put 123 as the input those ifs are skipped. But the condition is if(a > 99), 120 is more than 99. I don’t understand.

Answer 1

there are several errors in your code:

First the += operator of the string type takes a “const string&”, so instead of doing this:

risultato += (v_twenty_to_ninety[decine-2])

you need to pass it like this:

risultato += v_twenty_to_ninety[decine-2].c_str();

also here

decine = (a-(centinaia*100)/10);

you are using “centinaia” which at this point is zero because you only made the calculation inside the if(a > 99) if block and also the /10 should be outside the parentesis like this:

decine = (a-(centinaia*100))/10

So you need to move this centinaia = a/100; outside the if, so all 3 if statement gets the calculated variable (same with the other two).

this:

int unita = 0;
int decine = 0;
int centinaia = a/100;

to this:

int centinaia = a/100;
int decine    = (a-(centinaia*100))/10;
int unita     = (a-(centinaia*100)-(decine*10));

I made this changes to your method, It now look like this:

string scriviNumeroMinoreMille(int a)
{
    vector<string> v_zero_to_nineteen(20);
    vector<string> v_twenty_to_ninety(8);

    v_zero_to_nineteen = {"zero", "uno", "due", "tre", "quattro", "cinque", "sei", "sette", "otto", "nove", "dieci", "undici",
                          "dodici", "tredici", "quattordici", "quindici", "sedici", "diciassette", "diciotto", "diciannove"};

    v_twenty_to_ninety = {"venti", "trenta", "quaranta", "cinquanta", "sessanta", "settanta", "ottanta", "novanta"};

    string risultato;

    if(a == 0)
    {
        return risultato = "";
    }
    else if(a < 20 && a > 0)
    {
        return risultato = v_zero_to_nineteen[a];
    }
    else if(a == 20 || a == 30 || a == 40 || a == 50 || a == 60 || a == 70 || a == 80 || a == 90)
    {
        return risultato = v_twenty_to_ninety[(a/10)-2];
    }
    else if(a == 100)
    {
        return risultato = "cento";
    }

    int centinaia = a/100;
    int decine    = (a-(centinaia*100))/10;
    int unita     = (a-(centinaia*100)-(decine*10));

    if(a > 99)
    {

       risultato += v_zero_to_nineteen[centinaia].c_str();
       risultato += "cento";


    }
    if(a > 19)
    {
        if(a-(centinaia*100)%10 == 0)
        {
            risultato += v_twenty_to_ninety[decine-2].c_str();
        }
        else
        {
            risultato += v_twenty_to_ninety[decine-2].c_str();

            risultato += v_zero_to_nineteen[unita].c_str();
        }
    }
    return risultato;
}

For the 123 input it outputs “unocentoventitre”, I dont know if thats correct since I dont speak italian xD

Hope it helps.

EDIT: forgot to remove/change back the lines I inserted for testing.