Added VERY old code. Very cringy to look at, but hey, we all had to start somewhere...

OSU Coursework/CS 261 - Data Structures/Assignment 2/calc.c

@@ -0,0 +1,146 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "dynamicArray.h"
+
+
+/* param: s the string
+   param: num a pointer to double
+   returns: true (1) if s is a number else 0 or false.
+   postcondition: if it is a number, num will hold
+   the value of the number
+*/
+int isNumber(char *s, double *num)
+{
+	char *end;
+	double returnNum;
+
+	if(strcmp(s, "0") == 0)
+	{
+		*num = 0;
+		return 1;
+	}
+	else 
+	{
+		returnNum = strtod(s, &end);
+		/* If there's anythin in end, it's bad */
+		if((returnNum != 0.0) && (strcmp(end, "") == 0))
+		{
+			*num = returnNum;
+			return 1;
+		}
+	}
+	return 0;  //if got here, it was not a number
+}
+
+/*	param: stack the stack being manipulated
+	pre: the stack contains at least two elements
+	post: the top two elements are popped and 
+	their sum is pushed back onto the stack.
+*/
+void add (struct DynArr *stack)
+{
+	/* FIXME: You will write this function */
+}
+
+/*	param: stack the stack being manipulated
+	pre: the stack contains at least two elements
+	post: the top two elements are popped and 
+	their difference is pushed back onto the stack.
+*/
+void subtract(struct DynArr *stack)
+{
+	/* FIXME: You will write this function */
+}
+
+/*	param: stack the stack being manipulated
+	pre: the stack contains at least two elements
+	post: the top two elements are popped and 
+	their quotient is pushed back onto the stack.
+*/
+void divide(struct DynArr *stack)
+{
+	/* FIXME: You will write this function */
+}
+
+double calculate(int numInputTokens, char **inputString)
+{
+	int i;
+	double result = 0.0;
+	char *s;
+	struct DynArr *stack;
+
+	//set up the stack
+	stack = createDynArr(20);
+
+	// start at 1 to skip the name of the calculator calc
+	for(i=1;i < numInputTokens;i++) 
+	{
+		s = inputString[i];
+
+		// Hint: General algorithm:
+		// (1) Check if the string s is in the list of operators.
+		//   (1a) If it is, perform corresponding operations.
+		//   (1b) Otherwise, check if s is a number.
+		//     (1b - I) If s is not a number, produce an error.
+		//     (1b - II) If s is a number, push it onto the stack
+
+		if(strcmp(s, "+") == 0)
+			add(stack);
+		else if(strcmp(s,"-") == 0)
+			subtract(stack);
+		else if(strcmp(s, "/") == 0)
+			divide(stack);
+		else if(strcmp(s, "x") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Multiplying\n");
+		else if(strcmp(s, "^") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Power\n");
+		else if(strcmp(s, "^2") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Squaring\n");
+		else if(strcmp(s, "^3") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Cubing\n");
+		else if(strcmp(s, "abs") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Absolute value\n");
+		else if(strcmp(s, "sqrt") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Square root\n");
+		else if(strcmp(s, "exp") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Exponential\n");
+		else if(strcmp(s, "ln") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Natural Log\n");
+		else if(strcmp(s, "log") == 0)
+			/* FIXME: replace printf with your own function */
+			printf("Log\n");
+		else 
+		{
+			// FIXME: You need to develop the code here (when s is not an operator)
+			// Remember to deal with special values ("pi" and "e")
+			
+		}
+	}	//end for 
+
+	/* FIXME: You will write this part of the function (2 steps below) 
+	 * (1) Check if everything looks OK and produce an error if needed.
+	 * (2) Store the final value in result and print it out.
+	 */
+	
+	return result;
+}
+
+int main(int argc , char** argv)
+{
+	// assume each argument is contained in the argv array
+	// argc-1 determines the number of operands + operators
+	if (argc == 1)
+		return 0;
+
+	calculate(argc,argv);
+	return 0;
+}