T AP_pow(T x, T y, T p) {
T z;
assert(x);
assert(y);
assert(y->sign == 1);
assert( (!p) || (p->sign==1 && !iszero(p) && !isone(p)));
if (iszero(x))
return AP_new(0);
if (iszero(y))
return AP_new(1);
if (isone(x))
return AP_new((((y)->digits[0]&1) == 0) ? 1 : x->sign);
if (p)
if (isone(y))
z = AP_mod(x, p);
else {
T y2 = AP_rshift(y, 1), t = AP_pow(x, y2, p);
z = mulmod(t, t, p);
AP_free(&y2);
AP_free(&t);
if (!(((y)->digits[0]&1) == 0)) {
z = mulmod(y2 = AP_mod(x, p), t = z, p);
AP_free(&y2);
AP_free(&t);
}
}
else if (isone(y))
z = AP_addi(x, 0);
else {
T y2 = AP_rshift(y, 1), t = AP_pow(x, y2, NULL);
z = AP_mul(t, t);
AP_free(&y2);
AP_free(&t);
if (!(((y)->digits[0]&1) == 0)) {
z = AP_mul(x, t = z);
AP_free(&t);
}
}
return z;
}
int main(int argc, char *argv[]) {
int c;
sp = Stack_new();
Fmt_register('D', AP_fmt);
while ((c = getchar()) != EOF)
switch (c) {
case ' ': case '\t': case '\n': case '\f': case '\r':
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9': {
char buf[512];
{
int i = 0;
for ( ; c != EOF && isdigit(c); c = getchar(), i++)
if (i < (int)sizeof (buf) - 1)
buf[i] = c;
if (i > (int)sizeof (buf) - 1) {
i = (int)sizeof (buf) - 1;
Fmt_fprint(stderr,
"?integer constant exceeds %d digits\n", i);
}
buf[i] = 0;
if (c != EOF)
ungetc(c, stdin);
}
Stack_push(sp, AP_fromstr(buf, 10, NULL));
break;
}
case '+': {
AP_T y = pop(), x = pop();
Stack_push(sp, AP_add(x, y));
AP_free(&x);
AP_free(&y);
break;
}
case '-': {
AP_T y = pop(), x = pop();
Stack_push(sp, AP_sub(x, y));
AP_free(&x);
AP_free(&y);
break;
}
case '*': {
AP_T y = pop(), x = pop();
Stack_push(sp, AP_mul(x, y));
AP_free(&x);
AP_free(&y);
break;
}
case '/': {
AP_T y = pop(), x = pop();
if (AP_cmpi(y, 0) == 0) {
Fmt_fprint(stderr, "?/ by 0\n");
Stack_push(sp, AP_new(0));
} else
Stack_push(sp, AP_div(x, y));
AP_free(&x);
AP_free(&y);
break;
}
case '%': {
AP_T y = pop(), x = pop();
if (AP_cmpi(y, 0) == 0) {
Fmt_fprint(stderr, "?%% by 0\n");
Stack_push(sp, AP_new(0));
} else
Stack_push(sp, AP_mod(x, y));
AP_free(&x);
AP_free(&y);
break;
}
case '^': {
AP_T y = pop(), x = pop();
if (AP_cmpi(y, 0) <= 0) {
Fmt_fprint(stderr, "?nonpositive power\n");
Stack_push(sp, AP_new(0));
} else
Stack_push(sp, AP_pow(x, y, NULL));
AP_free(&x);
AP_free(&y);
break;
}
case 'd': {
AP_T x = pop();
Stack_push(sp, x);
Stack_push(sp, AP_addi(x, 0));
break;
}
case 'p': {
AP_T x = pop();
Fmt_print("%D\n", x);
Stack_push(sp, x);
break;
}
case 'f':
if (!Stack_empty(sp)) {
Stack_T tmp = Stack_new();
while (!Stack_empty(sp)) {
AP_T x = pop();
Fmt_print("%D\n", x);
Stack_push(tmp, x);
}
while (!Stack_empty(tmp))
Stack_push(sp, Stack_pop(tmp));
Stack_free(&tmp);
}
break;
case '~': {
AP_T x = pop();
Stack_push(sp, AP_neg(x));
AP_free(&x);
break;
}
case 'c': while (!Stack_empty(sp)) {
AP_T x = Stack_pop(sp);
AP_free(&x);
} break;
case 'q': while (!Stack_empty(sp)) {
AP_T x = Stack_pop(sp);
AP_free(&x);
}
Stack_free(&sp);
return EXIT_SUCCESS;
default:
if (isprint(c))
Fmt_fprint(stderr, "?'%c'", c);
else
Fmt_fprint(stderr, "?'\\%03o'", c);
Fmt_fprint(stderr, " is unimplemented\n");
break;
}
while (!Stack_empty(sp)) {
AP_T x = Stack_pop(sp);
AP_free(&x);
}
Stack_free(&sp);
return EXIT_SUCCESS;
}
