Nimber arithmetic: Difference between revisions

Line 813:

<lang rust>// highest power of 2 that divides a given number

fn hpo2(n : u32) -> u32 {

fn hpo2(n: u32) -> u32 {

n & (0xFFFFFFFF - n + 1)

}

// base 2 logarithm of the highest power of 2 dividing a given number

fn lhpo2(n : u32) -> u32 {

fn lhpo2(n: u32) -> u32 {

let mut q : u32 = 0;

let mut q: u32 = 0;

let mut m : u32 = hpo2(n);

let mut m: u32 = hpo2(n);

while m % 2 == 0 {

m >>= 1;

Line 829:

// nim-sum of two numbers

fn nimsum(x : u32, y : u32) -> u32 {

fn nimsum(x: u32, y: u32) -> u32 {

x ^ y

}

// nim-product of two numbers

fn nimprod(x : u32, y : u32) -> u32 {

fn nimprod(x: u32, y: u32) -> u32 {

if x < 2 || y < 2 {

return x * y;

}

let mut h : u32 = hpo2(x);

let mut h: u32 = hpo2(x);

if x > h {

return nimprod(h, y) ^ nimprod(x ^ h, y);

Line 845:

return nimprod(y, x);

}

let xp : u32 = lhpo2(x);

let xp: u32 = lhpo2(x);

let yp : u32 = lhpo2(y);

let yp: u32 = lhpo2(y);

let comp : u32 = xp & yp;

let comp: u32 = xp & yp;

if comp == 0 {

return x * y;

Line 855:

}

fn print_table(n : u32, op : char, func : fn(u32, u32) -> u32) {

fn print_table(n: u32, op: char, func: fn(u32, u32) -> u32) {

print!(" {} |", op);

for a in 0..=n {

Line 878:

println!();

print_table(15, '*', nimprod);

let a : u32 = 21508;

let a: u32 = 21508;

let b : u32 = 42689;

let b: u32 = 42689;

println!("\n{} + {} = {}", a, b, nimsum(a, b));

println!("{} * {} = {}", a, b, nimprod(a, b));