Nimber arithmetic: Difference between revisions
Added Rust solution
m (Removed unnecessary braces) |
(Added Rust solution) |
||
Line 352:
* | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
--- ------------------------------------------------
0 | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1 | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
2 | 0 2 3 1 8 10 11 9 12 14 15 13 4 6 7 5
3 | 0 3 1 2 12 15 13 14 4 7 5 6 8 11 9 10
4 | 0 4 8 12 6 2 14 10 11 15 3 7 13 9 5 1
5 | 0 5 10 15 2 7 8 13 3 6 9 12 1 4 11 14
6 | 0 6 11 13 14 8 5 3 7 1 12 10 9 15 2 4
7 | 0 7 9 14 10 13 3 4 15 8 6 1 5 2 12 11
8 | 0 8 12 4 11 3 7 15 13 5 1 9 6 14 10 2
9 | 0 9 14 7 15 6 1 8 5 12 11 2 10 3 4 13
10 | 0 10 15 5 3 9 12 6 1 11 14 4 2 8 13 7
11 | 0 11 13 6 7 12 10 1 9 2 4 15 14 5 3 8
12 | 0 12 4 8 13 1 9 5 6 10 2 14 11 7 15 3
13 | 0 13 6 11 9 4 15 2 14 3 8 5 7 10 1 12
14 | 0 14 7 9 5 11 2 12 10 4 13 3 15 1 8 6
15 | 0 15 5 10 1 14 4 11 2 13 7 8 3 12 6 9
21508 + 42689 = 62149
21508 * 42689 = 35202
</pre>
=={{header|Rust}}==
{{trans|FreeBASIC}}
<lang rust>// highest power of 2 that divides a given number
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 {
let mut q : u32 = 0;
let mut m : u32 = hpo2(n);
while m % 2 == 0 {
m >>= 1;
q += 1;
}
q
}
// nim-sum of two numbers
fn nimsum(x : u32, y : u32) -> u32 {
x ^ y
}
// nim-product of two numbers
fn nimprod(x : u32, y : u32) -> u32 {
if x < 2 || y < 2 {
return x * y;
}
let mut h : u32 = hpo2(x);
if x > h {
return nimprod(h, y) ^ nimprod(x ^ h, y);
}
if hpo2(y) < y {
return nimprod(y, x);
}
let xp : u32 = lhpo2(x);
let yp : u32 = lhpo2(y);
let comp : u32 = xp & yp;
if comp == 0 {
return x * y;
}
h = hpo2(comp);
nimprod(nimprod(x >> h, y >> h), 3 << (h - 1))
}
fn print_table(n : u32, op : char, func : fn(u32, u32) -> u32) {
print!(" {} |", op);
for a in 0..=n {
print!("{:3}", a);
}
print!("\n--- -");
for _ in 0..=n {
print!("---");
}
println!();
for b in 0..=n {
print!("{:2} |", b);
for a in 0..=n {
print!("{:3}", func(a, b));
}
println!();
}
}
fn main() {
print_table(15, '+', nimsum);
println!();
print_table(15, '*', nimprod);
let a : u32 = 21508;
let b : u32 = 42689;
println!("\n{} + {} = {}", a, b, nimsum(a, b));
println!("{} * {} = {}", a, b, nimprod(a, b));
}</lang>
{{out}}
<pre>
+ | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
--- -------------------------------------------------
0 | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 | 1 0 3 2 5 4 7 6 9 8 11 10 13 12 15 14
2 | 2 3 0 1 6 7 4 5 10 11 8 9 14 15 12 13
3 | 3 2 1 0 7 6 5 4 11 10 9 8 15 14 13 12
4 | 4 5 6 7 0 1 2 3 12 13 14 15 8 9 10 11
5 | 5 4 7 6 1 0 3 2 13 12 15 14 9 8 11 10
6 | 6 7 4 5 2 3 0 1 14 15 12 13 10 11 8 9
7 | 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8
8 | 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7
9 | 9 8 11 10 13 12 15 14 1 0 3 2 5 4 7 6
10 | 10 11 8 9 14 15 12 13 2 3 0 1 6 7 4 5
11 | 11 10 9 8 15 14 13 12 3 2 1 0 7 6 5 4
12 | 12 13 14 15 8 9 10 11 4 5 6 7 0 1 2 3
13 | 13 12 15 14 9 8 11 10 5 4 7 6 1 0 3 2
14 | 14 15 12 13 10 11 8 9 6 7 4 5 2 3 0 1
15 | 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
* | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
--- -------------------------------------------------
0 | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1 | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
| |||