Editor’s note: this is not actually what compilers do, and gives the wrong answer for large positive integers ending with 9, starting with div10(1073741829) = 107374183 not 107374182 (Godbolt). It is exact for inputs smaller than 0x40000005, though, which may be sufficient for some uses. Compilers (including MSVC) do use fixed-point multiplicative inverses for constant … Read more
Consistency. You’ll need to follow some very basic and seemingly irrelevant explanations to understand it. In school you have learned division with a remainder. And you have done calculations like this: 8 ÷ 4 = 2 R 0 7 ÷ 4 = 1 R 3 6 ÷ 4 = 1 R 2 5 ÷ 4 … Read more
If your modulus / divisor is a known constant, and you care about performance, see this and this. A multiplicative inverse is even possible for loop-invariant values that aren’t known until runtime, e.g. see https://libdivide.com/ (But without JIT code-gen, that’s less efficient than hard-coding just the steps necessary for one constant.) Never use div for … Read more
For the actual values, i.e. 8.0/(-7.0), the result is roughly -1.143. Your result using integer division is being rounded down toward the more negative value of -2. (This is also known as “Floor division”) This is why you will get the somewhat perplexing answers of: >>> 8/(-7) -2 >>> 8/7 1 Note: This is “fixed” … Read more
There are at least 2 reasonable answers to this question. (I originally gave only answer 2.) Use the int() function to truncate the floating-point calculation result to an integer (throwing away the decimal part), as Bryan suggested in his self-answer: #539805 Use the use integer pragma to make Perl truncate both the inputs and results … Read more
Because the conversion to float happens after the division has been done. You need: float percentage = ((float) totalOptCount) / totalRespCount; You should be able to format using something like: String str = String.format(“%2.02f”, percentage);
But why Python // choose to round towards negative infinity? I’m not sure if the reason why this choice was originally made is documented anywhere (although, for all I know, it could be explained in great length in some PEP somewhere), but we can certainly come up with various reasons why it makes sense. One … Read more
Cast the operands to floats: float ans = (float)a / (float)b;
The standard idiom for integer rounding up is: int a = (59 + (4 – 1)) / 4; You add the divisor minus one to the dividend.
The operands of the binary operation 3 / 10 are untyped constants. The specification says this about binary operations with untyped constants if the operands of a binary operation are different kinds of untyped constants, the operation and, for non-boolean operations, the result use the kind that appears later in this list: integer, rune, floating-point, … Read more