int main()
{
double op2;
char buf[BUFSIZ];
int result;
infix2postfix(buffer);
puts(buffer);
while ((result = getop2(buf) != EOF)) {
switch (result) {
case '+':
STACK_push(STACK_pop() + STACK_pop());
break;
case '*':
STACK_push(STACK_pop() * STACK_pop());
break;
case '/':
op2 = STACK_pop();
if (op2 == 0) {
error("zero divisor\n");
}
STACK_push(STACK_pop() / op2);
break;
case '-':
op2 = STACK_pop();
STACK_push(STACK_pop() / op2);
break;
case '$':
STACK_push(sqrt(STACK_pop()));
break;
case NUMBER:
STACK_push(atof(buf));
break;
case '\n':
printf("%f\n", STACK_pop());
break;
default:
error("unrecognize character %c\n", result);
break;
}
}
return 0;
}
/* reverse Polish calculator */
int main(void) {
int type;
double op2;
char s[MAXOP];
while ((type = getop2(s)) != EOF) {
switch (type) {
case NUMBER:
push(atof(s));
break;
case '+':
push(pop() + pop());
break;
case '*':
push(pop() * pop());
break;
case '-':
op2 = pop();
push(pop() - op2);
break;
case '/':
op2 = pop();
if (op2 != 0.0)
push(pop() / op2);
else
printf("error: zero divisor\n");
break;
case '%':
op2 = pop();
if (op2 != 0.0)
push(fmod(pop(),op2));
else
printf("error: modulo by zero\n");
break;
case '\n':
printf("\t%.8g\n", pop());
break;
default:
printf("error: unknown command %s\n", s);
}
}
return 0;
}
