What is causing my blackjack program to crash before doing anything? - c

Question

When I run my program, it will print "Welcome to Blackjack! Rules: " and then an error window will come up saying "Blackjack.exe has stopped working and I have to close the program. In the compiler window it says "Process terminated". How do I stop this from happening?
Is one of the loops not working correctly?
My code:
#include <stdio.h>
#include <stdlib.h>
void Initializedeck(int[]);
void Shuffledeck(int[]);
void displayscore(int, int);
int hdrawcards(int[], int[]);
char getsuit(int);
int cdrawcards(int[], int[]);
int main()
{
int deck[52];
char cont;
int hcherries=10;
int ccherries=10;
int hcards[10];
int ccards[10];
int htotal;
int ctotal;
printf("Welcome to Blackjack!\n");
printf("Rules: \n ");
Initializedeck(deck);
cont='y';
while(cont=='y')
{
Shuffledeck(deck);
system("cls");
displayscore(hcherries, ccherries);
htotal=hdrawcards(hcards, deck);
ctotal=cdrawcards(ccards, deck);
if(htotal>ctotal)
{
printf("You Win!");
}
else
{
printf("Computer Wins. :( ");
}
printf("Do you want to continue?(y/n)");
scanf("%c", &cont);
}
return 0;
}
void Initializedeck(int deck[])
{
int i=0;
while(i<52)
{
deck[i]=i;
i++;
}
}
void Shuffledeck(int deck[])
{
int hold;
int max=51;
int random;
while(max>=0)
{
random=rand()%(max)+1;
hold=deck[max];
deck[max]=random;
random=hold;
max--;
}
}
void displayscore(int hcherries, int ccherries)
{
printf("Human: %i(cherries) Computer: %i(cherries)", hcherries, ccherries);
}
int hdrawcards(int hcards[], int deck[])
{
char answer;
int i=0;
int score=0;
int total=0;
char rank;
int worth;
char suit;
int card;
printf("Do you want to draw a card? (y/n)");
scanf("%c", &answer);
while(answer=='y' && total<21)
{
score=score+deck[i];
hcards[i]=deck[i];
card=hcards[i];
worth=hcards[i]%13;
if(worth==10)
{
rank='T';
}
else if (worth==11)
{
rank='J';
}
else if (worth==12)
{
rank='Q';
}
else if (worth==13)
{
rank='K';
}
else if(worth==1)
{
rank='A';
}
else
{
rank=worth;
}
if(worth>10)
{
worth=10;
}
total=total+worth;
suit=getsuit(card);
printf("%c%c\n", rank, suit);
printf("Total: %i", total);
i++;
scanf("%c", &answer);
}
return total;
}
int cdrawcards(int ccards[], int deck[])
{
int i=26;
int total;
int score;
int worth;
char rank;
char suit;
int card;
while(total<18)
{
score=score+deck[i];
ccards[i]=deck[i];
card=ccards[i];
worth=ccards[i]%13;
if(worth==10)
{
rank='T';
}
else if (worth==11)
{
rank='J';
}
else if (worth==12)
{
rank='Q';
}
else if (worth==13)
{
rank='K';
}
else if(worth==1)
{
rank='A';
}
else
{
rank=worth;
}
if(worth>10)
{
worth=10;
}
total=total+worth;
suit=getsuit(card);
printf(" %c%c\n", rank, suit);
printf(" Total: %i", total);
i++;
}
return total;
}
char getsuit(int card)
{
char suit;
if(card<13)
{
suit='S';
}
else if(card>=13 && card<26)
{
suit='H';
}
else if(card>=26 && card<39)
{
suit='D';
}
else if(card>=39 && card<52)
{
suit='C';
}
return suit;
}

Answer 1

You have an array overflow in cdrawcards():
int ccards[10];
...
ctotal = cdrawcards(ccards, deck);
...
int cdrawcards(int ccards[], int deck[])
{
int i = 26;
...
ccards[i] = deck[i]; //Overflow, ccards[] only has 10 elements
Either change the initial value of i or make the array larger int ccards[52]. I would also add an explicit check in cdrawcards() and hdrawcards() to ensure you don't overflow the arrays, like:
while (total < 18 && i < 10)
For example, in hdrawcards() you can overflow the array if you get a bunch of low value cards in a row (ex: 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3(overflow), 3, ...).