Go Fish game - program stops abruptly and won't enter loop

[Heymid]

I'm writing a Go Fish command-line program in C++. I'm using Xcode. However, for some reason, the program won't enter the for loop at the end of the code. I'm thinking it has to do with the program not generating a number 0, but I've looked through the code several times and I am unable to exactly pinpoint the problem. Here is my code:

//
//  main.cpp
//  hugetest
//
//  Created by Måns Nilsson on 2013-09-22.
//  Copyright (c) 2013 Måns Nilsson. All rights reserved.
//

#include <iostream>
#include <string>

using namespace std;

int main(int argc, const char * argv[])
{
    srand(unsigned(time(0)));
    int player[4][30], tagen[52], sjon[46], random, antal, spelare_fraga, kort_fraga_real;
    string kort_fraga;
    
    cout<<"How many players? (2-4): ";
    cin >>antal;
    
    while (antal != 2 && antal != 3 && antal != 4) {
        cout<<"You must choose between 2-4 players! Try again: ";
        
        cin.clear();
        
        cin >>antal;
    }
    
    for (int k = 0, a = 0, b = 0;a<antal * 3;k++, a++) {
        if (k == antal) {
            k = 0;
            b++;
        }
        else { }
        
        random = (rand()%52);
        
        while (tagen[random] == 1) {
            random = (rand()%52);
        }
        
        player[k][b] = random;
        tagen[random] = 1;
    }
    
    
    
    
    cout<<"Player 1's cards: "<<endl;
    for (int k = 0;k<3;k++) {
        cout<<player[0][k]<<endl;
    }
    cout<<"Player 2's cards: "<<endl;
    for (int k = 0;k<3;k++) {
        cout<<player[1][k]<<endl;
    }
    
    cout<<"The sea cards: "<<endl;
    for (int a = 0;a<52 - (antal * 3);a++) {
        random = (rand()%52);
        
        while (tagen[random] == 1) {
            random = (rand()%52);
        }
        
        sjon[a] = random;
        tagen[random] = 1;
        cout<<sjon[a]<<endl;
    }
    
    for (int k = 0;k<4;k++) {
        if (k == antal) {
            k = 0;
        }
        else { }
        
        cout<<"Player "<<k + 1<<", who do you wish to ask? Choose a number between 1-"<<antal<<" but not yourself: ";
        cin >>spelare_fraga;
        
        cout<<"Which card would you like to ask player "<<spelare_fraga<<" about?: ";
        kort_fraga = "";
        cin >>kort_fraga;
        if (kort_fraga == "ESS" || kort_fraga == "Ess" || kort_fraga == "ess" || kort_fraga == "ÄSS" || kort_fraga == "Äss" || kort_fraga == "äss") {
            kort_fraga_real = 1;
        }
        else if (kort_fraga == "KNEKT" || kort_fraga == "Knekt" || kort_fraga == "knekt" || kort_fraga == "KNÄKT" || kort_fraga == "Knäkt" || kort_fraga == "knäkt") {
            kort_fraga_real = 11;
            
        }
        else if (kort_fraga == "DAM" || kort_fraga == "Dam" || kort_fraga == "dam") {
            kort_fraga_real = 12;
        }
        else if (kort_fraga == "KUNG" || kort_fraga == "Kung" || kort_fraga == "kung") {
            kort_fraga_real = 13;
        }
        else if (kort_fraga.size() == 2) {
                kort_fraga_real = ((kort_fraga[0] - '0') * 10) + (kort_fraga[1] - '0');
            }
        else {
                kort_fraga_real = kort_fraga[0] - '0';
            }
        
    }
}

I'm expecting the program to give player 1 three random cards between 0-51, and player 2 three other random cards between 0-51, and then the sea should get the remaining 46 cards between 0-51. The program stops abruptly after giving out the cards.

[Mats]

for (int k = 0;k<4;k++) {
        if (k == antal) {
            k = 0;
        }
        else { }

Blank else? Hmm...

Also, you can put in 3 or 4 players, but you only deal to two players. I would also suggest using an array to hold a standard 52 card deck for Go Fish, since it's a set matching game which really requires a standard deck with 4 of each number.

[Heymid]

I just found out what the problem was. I had to declare all array values as 0 before beginning. I achieved this by adding for loops, and the program now works as expected. From now on, I will always declare the values for all array indexes before beginning.

My plan is to have the four A's (1's) as cards 1-4, the four 2's as cards 5-8, the four 3's as cards 9-12 and so on. Because we've generated 52 random cards, no cards can have the same value. If a card slot has the value 0, it will be treated as a non-card (or an empty slot). (I've also modified the code so the program now generates numbers between 1-52, not 0-51.)

By the way, are empty elses problematic? I don't think so, because it tells the program that, should none of the other conditions be met, nothing should happen.

[Mats]

If there is no else, nothing else will happen anyway.

Also note that rand() % 52 generates numbers 0-51 inclusive. You also might get an overflow on player[4][30]. Why not just make it [4][52] and never ever ever have the issue of that overflow? ;)

[Heymid]

As I said, it clarifies that nothing should happen if none of the conditions in the preceding if statements are met. Regarding the overflow, I first considered it unlikely that a player would ever have over 30 cards in their hand at once, but I've changed it to [4][52] now.