Page 70 - DCAP605_ADVANCED_DATA_STRUCTURE_AND_ALGORITHMS

Unit 3: Stacks

char pop(stk *stack); Notes
char stackTop(stk *stack);
int isEmpty(stk *stack);
int isFull(stk *stack);
void printResult(char infix[], char postfix[]);
/*void print_msg(void);*/
/* program entry point */
int main(void)
{
char infix[20], postfix[20]=””;
/* convert from infix to postfix main function */
convertToPostfix(infix, postfix);
/* display the postfix equivalent */
infix[strlen(infix)-2] = ‘\0’;
printResult(infix, postfix);
return(1);
}
void initStack(stk *stack) /* initalise the stack */
{
stack->top = -1; /* stack is initially empty */
}
void get_infix(char infix[]) /* get infix expression from user */
{
int i;
printf(“Enter infix expression below (max 18 characters excluding spaces) : \n”);
fflush(stdin);
for ( i=0; i<18; ) /* to read in only 18 characters excluding spaces */
{
if ( (infix[i] = getchar()) == ‘\n’ )
{
i++; break;
}
else if ( !(isspace(infix[i])) )
i++;
}
infix[i] = ‘\0’;
}
void convertToPostfix(char infix[], char postfix[]) /* convert the infix expression
to postfix notation */
{
int i, length, j=0;

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