04-03-2025, 10:11 PM
Even an integer 64 handles up to 19 digits without problem: 9,223,372,036,854,775,807
Since 9 digits * 9 digits = max 18 digits, you'd still be able to hold the answer without overflow.
As for tracking any sort of sign.... *WHY* for goodness's sake?!
Do this:
positive * positive = positive
negative * negative = positive
positive * negative = negative
negative * positive = negative
Simple rule, settled from the beginning with your numbers and now you're only dealing with the positive values with the sign safely already stored off to the side.
3 * 3 .... positive numbers only
-3 * -3 .... negative * negative = positive so it's just the same as 3 * 3
-3 * 3 .... negative * positive = negated (3 * 3)
Either way, you're always just doing multiplication with positive values... The sign of the answer is sorted out easily elsewhere in the code.
Since 9 digits * 9 digits = max 18 digits, you'd still be able to hold the answer without overflow.
As for tracking any sort of sign.... *WHY* for goodness's sake?!
Do this:
positive * positive = positive
negative * negative = positive
positive * negative = negative
negative * positive = negative
Simple rule, settled from the beginning with your numbers and now you're only dealing with the positive values with the sign safely already stored off to the side.
3 * 3 .... positive numbers only
-3 * -3 .... negative * negative = positive so it's just the same as 3 * 3
-3 * 3 .... negative * positive = negated (3 * 3)
Either way, you're always just doing multiplication with positive values... The sign of the answer is sorted out easily elsewhere in the code.