/*
 * **** HISTORY *****
 *
 * Filename: test.c
 * Synopsis: test
 *
 * This is a simple program that will take input from the keyboard and then
 * print each line of input to screen.
 * Version 0.1 - Program simply returned a string of characters that had been
 * entered using printf.
 * version 0.2 - program differentiated between a string of characters and an
 * integer.
 * version 0.3 - Fixed a bug in the code that caused a 0 integer to be printed
 * after characters. Originally believed it to be a null byte, later discovered
 * that it was, in fact, a flaw in my if statements since I hadn't used else.
 * the use of else and else if in the testing area of the program are important
 * so that characters aren't printed as characters then passed down to be converted
 * into integers.
 * version 0.4 - program began to differentiate between characters, an operand
 * and the specific operators +, -, /, x and =. I was able to tell that the
 * differentiation had been made by asking the program to print out which each
 * was, for example: If I had entered: test 1 a + the program would output:
 * Integer: 1, Character: a, Symbol +.
 * version 0.5 - Array was defined from code that had been written in p3.c which was
 * written at an earlier date. This is where p3.c and test.c began to merge as
 * the final solution to p3.c with p3.c merging into test.c.
 */

 #include 
 #include 

 
 /*
 * define is used to make modification of each easier. It is also good for readability.
 * Characters A - D will be assigned values that the user wishes to store so that they
 * can later be used by, for example, 2 A +.
 */
 
 #define stack empty
 #define MemoryA A
 #define MemoryB B
 #define MemoryC C
 #define MemoryD D

/*
 * I need to define my array that will be used in a similar way to how I understand a
 * stack. The type of array that I will use is a fixed-length array so that the program
 * size will have a limit of 20 elements.
 *              See Page 112 - C In a Nutshell
 */

    int top = 0;                /*Pointer to keep track of where the top of the stack/array is*/
    //int maxstack = 20;  /*Allocates the maximum value of the stack-array */
    int stack[50];      /*sets the array stack equal of the maximum value of the stack*/

    void push(int x);

/*
 * The push function will push a new entry onto the stack at the stack pointer "top".
 * Once the entry (passed in as x) has been assigned as an element to the stack the
 * "stack pointer" top will then increment by one so that it is pointing to the next
 * free space.
 */
  void push(int x)
  {
        stack[top] = x;
        top ++;
  }
 


int main (int argc, char *argv[])
{
        int i;
        int j = 0;
        for (i = 1; i < argc; i++)
        {
                for(j=0; j < strlen(argv[i]); j++)
                {
                        /*This is a test to see if a the input is a
                         * alphabetical number. If it is, then the
                         * program will then check to see if it is
                         * specifically A, B, C or D.
                         */
                        if (isalpha(argv[i][j]))       
                        {
                                printf("Character: %s\n", argv[i]);
                        }      
                                       
                        /* These tests will test to see if input is an operand*/
                        else if (strcmp(argv[i], "+") == 0)
                        {
                                printf("Symbols: %s\n", argv[i]);
                        }
                        else if (strcmp(argv[i], "-") == 0)
                        {
                                printf("Symbols: %s\n", argv[i]);
                        }
                        else if (strcmp(argv[i], "/") == 0)
                        {
                                printf("Symbols: %s\n", argv[i]);
                        }
                        else if (strcmp(argv[i], "x") == 0){
                                printf("Symbols: %s\n", argv[i]);
                        }
                        /* else, it will be an integer.*/
                        else
                        {
                                int temp = atoi(argv[i]);
                                push (temp);                           
                                //int i = 0;
                               
                                printf("Stack: %d", stack[top]);
                               
                                //printf("Integer: %d\n",atoi(argv[i]));
                        }
               
                }
        }
}