int main( void ){
int type;
double operand;
char expression[MAX_POLISH_SIZE];
// instruction
printf("use ~ to represent sin operation.\n");
printf("use # to represent exp operation.\n");
printf("use @ to represent power operation.\n");
while((type=gettop(expression)) != EOF){
switch(type){
case NUMBER:
{ push(atof(expression)); break;}
case '+':
{ push(pop() + pop()); break;}
case '*':
{ push(pop() * pop()); break;}
case '-':
{ swaptop2(); push(pop() - pop()); break;}
case '/':
{ operand = peek(); swaptop2(); assert(operand != 0); push(pop() / pop()); break;}
case '%':
{ operand = peek(); swaptop2(); assert(operand != 0); push(mod(pop(), operand)); break;}
case '~': // sin
{ push(sin(pop())); break;}
case '#': // exp
{ push(exp(pop())); break;}
case '@': // power
{ operand = peek(); swaptop2(); push(pow(pop(), operand)); break;}
case '\n':
{ printf("\t%.8g\n", pop()); break;}
default:
{ printf("error happens.\n"); break;}
}
}
return 0;
}
/* reverse Polish calculator */
main()
{
int type;
double op2;
char s[MAXOP];
while ((type = getop(s)) != EOF)
{
switch (type)
{
case NUMBER:
push(atof(s));
break;
case '"':
duptop();
break;
case '\'':
printtop();
break;
case '!':
swaptop2();
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(((int) pop()) % (int) op2);
}
else
{
printf("error: zero divisor\n");
}
break;
case '^':
op2 = pop();
push(pow(pop(), op2));
break;
case '#':
push(exp(pop()));
break;
case '$':
push(sin(pop()));
break;
case '\n':
printf("\t%.8g\n", pop());
break;
default:
printf("error: unknown command %s\n", s);
break;
}
}
return 0;
}
// But it's a polish calculator
int main() {
int type;
double op2; // For div and sub, we need to do the operation backwards
char s[MAXOP];
while ( (type=getop(s)) != EOF ) {
switch (type) {
case NUMBER:
push(atof(s));
break;
case VARIABLE:
push(variables[s[0] - 'A']);
break;
case ASSIGN:
if (s[0] < 'A' || s[0] > 'Z')
printf("Error: Not a proper variable name\n");
else
variables[s[0] - 'A'] = pop();
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 division\n");
break;
case '%':
op2 = pop();
if (op2 != 0.0)
push((int)pop() % (int)op2);
else printf("Error: Zero division with modulus\n");
break;
case SIN:
push(sin(pop()));
break;
case COS:
push(cos(pop()));
break;
case TAN:
// Not bothering to worry about multiples of pi/2
push(tan(pop()));
break;
case EXP:
push(exp(pop()));
break;
case POW:
op2 = pop();
push(pow(pop(), op2));
break;
case 'd':
// d for duplicate
duptop();
break;
case 's':
// s for swap
swaptop2();
break;
case 'c':
// c for clear
clear();
break;
case '\n':
printf("\t%.8g\n", peek());
break;
default:
printf("Error: unknown command %s\n", s);
break;
}
}
return 0;
}
/* reverse Polish calculator */
main()
{
int type;
double op2, last, vars[26];
char s[MAXOP], varname;
while ((type = getop(s)) != EOF)
{
switch (type)
{
case NUMBER:
push(atof(s));
break;
case '"':
duptop();
break;
case '\'':
printtop();
break;
case '!':
swaptop2();
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(((int) pop()) % (int) op2);
}
else
{
printf("error: zero divisor\n");
}
break;
case '^':
op2 = pop();
push(pow(pop(), op2));
break;
case '#':
push(exp(pop()));
break;
case '$':
push(sin(pop()));
break;
case ASSIGNVAR:
varname = s[0];
duptop();
vars[varname - 'a'] = pop();
break;
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
case 'v': case 'w': case 'x': case 'y': case 'z':
push(vars[type - 'a']);
break;
case '?':
push(last);
break;
case '\n':
last = pop();
printf("\t%.8g\n", last);
break;
default:
printf("error: unknown command %s\n", s);
break;
}
}
return 0;
}
