NUMBER number_subtract(NUMBER num1, NUMBER num2) {
int borrow, sub, i, j, flip;
NUMBER tmp, res = number_new();
if (num2.negative) {
num2.negative = 0;
return number_add(num1, num2);
}
if (num1.negative) {
num1.negative = 0;
res = number_add(num2, num1);
res.negative = 1;
return res;
}
flip = !number_greater(num1, num2);
if (flip) {
tmp = num1;
num1 = num2;
num2 = tmp;
}
for (i = sub = borrow = 0; i < num1.numbers || i < num2.numbers || borrow; i++, sub = 0) {
if (num2.numbers > i)
sub = num2.number[i];
sub += borrow;
if (num1.numbers > i) {
num1.number[i] -= sub;
for (j = 0; num1.number[i] < 0; j++, num1.number[i] += 10);
number_insert_high(&res, num1.number[i]);
borrow = j;
} else {
number_insert_high(&res, sub % 10);
borrow = sub / 10;
}
}
if (flip)
res.negative = 1;
return res;
}
int main(int argc, char **argv) {
NUMBER num1, num2, num3;
char arg1[512], arg2[512];
fprintf(stderr, "Enter two numbers to add: ");
fscanf(stdin, "%s %s", arg1, arg2);
num1 = number_from_string(arg1);
num2 = number_from_string(arg2);
num3 = number_add(num1, num2);
fprintf(stderr, "(%s) + (%s) = %s\n", arg1, arg2, number_to_string(&num3));
fprintf(stderr, "Enter two numbers to subtract: ");
fscanf(stdin, "%s %s", arg1, arg2);
num1 = number_from_string(arg1);
num2 = number_from_string(arg2);
num3 = number_subtract(num1, num2);
fprintf(stderr, "(%s) - (%s) = %s\n", arg1, arg2, number_to_string(&num3));
return 0;
}
VALUE wrap_add(self, a, b){
return INT2FIX( number_add( FIX2INT(a), FIX2INT(b) ) );
}
