Question about assigning values

[DCMann2]

Hi everyone,

I'm trying to write a card counting program, but I'm a bit confused about something. I'm reading card data (like ace, queen, 5, etc.) from a text file, and each number card or face card is assigned a value of either 1, 0, or -1. Two through six are given a value of +1, seven through nine are given a value of 0, and ten through ace are given a value of -1. The program is supposed to add up all the cards from the text file and print a value, but I'm confused about how I'm supposed to tell the program what the values of the cards are so it can add them all up. I was thinking about using an if...else statement, but I'm not entirely sure how to make it work. I'll post the code and the text file if necessary.

[JDGATX]

Do you have any code to show currently?

Here is the general flow, in my mind:
1) fscanf() to read in a card
2) use a switch statement on the value of the card
3) Something like this pseudocode:

switch (card_value)
{
     case '2': case '3': case '4': case '5': case '6':
          sum += 1;
          break;
     // And so on...
}

[DCMann2]

This is all I have so far. Right now all it does is read from the file and display what the cards are on the screen, but I don't know how to tell the program what the value of each card is so it will add/subtract them.

int main(void)
{
    FILE* spCards;
    char charIn;
	int result = 0;
	
	printf("This program will count cards during a game of blackjack.\n");
	printf("It reads the cards from a file and prints the final +/- count\n");
	printf("for the cards dealt. Here are the values of the cards:\n");
	printf("2, 3, 4, 5, 6 = +1\n");
	printf("7, 8, 9 = 0\n");
	printf("T, J, Q, K, A = -1\n\n");

	spCards = fopen("location of my file", "r");
	        if (spCards == NULL)
	           {
                      printf("Error opening cards.txt for reading\n");
		      return (100);
	           }

    printf("For:\n");
    while((fscanf(spCards, "%c", &charIn)) == true)
        printf("%c", charIn);
     
        printf("\n\nFinal count is: %d\n", result);
        
    fclose(spCards);
	
  system("PAUSE");	
  return 0;
}

[JDGATX]

I've got a working program that does what you want, so feel free to ask any more questions you have.

[DCMann2]

I've got a working program that does what you want, so feel free to ask any more questions you have.

All I need to know is how to tell the program what the value of each card is so it will add it properly. Do I need to declare each card's value at the beginning of the program, or can I assign values to each card after the file is opened for reading? Once that's done, all that's left is to use something like result += (variable), right?

EDIT: If you could print the part of your code where you tell the program what the values are, that would be really helpful.

[JDGATX]

You're reading the values in from a text file, correct? This means that charIn will hold the value of each card once you read that in. Since it's a char data type, you just have to check to see what the value is. The switch statement that I suggested above accomplishes this check. A switch statement is very similar to a long string of if-else conditionals. Be sure to notice how, for each case, I check to see if the card is equal to '2', '3', '4', etc. Putting the values in single quotes tells the processor we're dealing with characters, not integers.

Code:

	while((fscanf(spCards, "%c%*c", &charIn)) == 1)   // Gets rid of the space separating the values in your text file
	{
		printf("%c, ", charIn);
		switch (charIn)
		{
		case '2': case '3': case '4': case '5': case '6':
			result += 1;
			break;
		case '7': case '8': case '9':
			break;     // Do nothing
		case 'T': case 'J': case 'Q': case 'K': case 'A':
			result -= 1;
		}
	}

Read the FAQ for more info. on switch statements.

[DCMann2]

I wrote a switch statement similar to what you provided a while ago, but the program is still giving me the wrong result, and I can't figure out why that's happening. It keeps giving me -1, even though I'm supposed to end up with -4 for the text file I was given.

Here's the code I have so far:

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

int main(void)
{
    FILE* spCards;
    char charIn;
    int result = 0;
	
	printf("This program will count cards during a game of blackjack.\n");
	printf("It reads the cards from a file and prints the final +/- count\n");
	printf("for the cards dealt. Here are the values of the cards:\n");
	printf("2, 3, 4, 5, 6 = +1\n");
	printf("7, 8, 9 = 0\n");
	printf("T, J, Q, K, A = -1\n\n");

	spCards = fopen("L:\\CIS 161\\Chapter VII Card Counting\\Card Counting\\Card Counting\\cards.txt", "r");
	        if (spCards == NULL)
	           {
                        printf("Error opening cards.txt for reading\n");
		        return (100);
	           }

    printf("For:\n");
    while((fscanf(spCards, "%c", &charIn)) == true)
    printf("%c", charIn);
    {
		switch (charIn)
		{
		case '2': case '3': case '4': case '5': case '6':
			result += 1;
			break;
		case '7': case '8': case '9':
			break;     
		case 'T': case 'J': case 'Q': case 'K': case 'A':
			result -= 1;
		}
	}
	fclose(spCards);
    
    printf("\n\nThe final count is: %d\n", result);
    printf("Thank you, and have a great day.\n\n");
    
  system("PAUSE");	
  return 0;
}

Here are the cards I was given, if it makes any difference (and yes, they're supposed to be vertical):
A
2
K
9
7
Q
A
A
4
T

[JDGATX]

You need to eat up the newline character. Look above at my code. You'll see how I added a %*c to eat up the newline.

Also, your brackets and indentation are screwy. Again, look at my code. It works.