int main(void) {
printf("f=");
formula *f_tree = input_formula();
if (f_tree) {
printf("f'="); out_derivative(f_tree); printf("\n");
} else
printf("Incorrect formula\n");
free_tree(f_tree);
return 0;
}
formula *next_formula_part() {
formula *res = NULL;
char c = getchar();
switch (c) {
case '(':
res = input_formula();
if (getchar() != ')') {
free_tree(res);
return NULL;
}
break;
case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case 'x':
res = (formula *)malloc(sizeof(formula));
res->smb = c; res->left = res->right = NULL;
break;
default:
break;
}
return res;
}
int calc(void)
{
char buf[1024];
double ret;
init_token_type();
f_was_calc = 1;
printf("> "); /* prompt */
if(input_formula(buf, sizeof(buf)) == -1) return -1;
if(to_RPN(buf) == -1) return -1;
ret = calc_RPN();
if(f_error) return 0;
append_variable_value("prev", ret);
if(variable_name[0] != '\0') {
append_variable_value(variable_name, ret);
}
/* real number or natural number */
if(f_was_calc)
print_style(ret);
return 0;
}
