Recaman's sequence: Difference between revisions

=={{header|Rust}}==

<syntaxhighlight lang="rust">

use std::collections::HashSet ;

fn main() {

let mut recamans : Vec<i32> = Vec::new( ) ;

let mut reca_set : HashSet<i32> = HashSet::new() ;

let mut first_nums : HashSet<i32> = HashSet::new( ) ;

for i in 0i32..=1000 {

first_nums.insert( i ) ;

}

recamans.push( 0 ) ;

reca_set.insert( 0 ) ;

let mut current : i32 = 0 ;

while ! first_nums.is_subset( &reca_set ) {

current += 1 ;

let mut nextnum : i32 = recamans[( current as usize ) - 1] - current ;

if nextnum < 0 || reca_set.contains( &nextnum ) {

nextnum = recamans[(current as usize ) - 1 ] + current ;

}

recamans.push( nextnum ) ;

reca_set.insert( nextnum ) ;

if current == 15 {

println!("The first 15 numbers of the Recaman sequence are:" ) ;

println!("{:?}" , recamans ) ;

}

}

println!("To generate all numbers from 0 to 1000 , one has to go to element {}" , current) ;

}</syntaxhighlight>

{{OUT}}

<pre>

The first 15 numbers of the Recaman sequence are:

[0, 1, 3, 6, 2, 7, 13, 20, 12, 21, 11, 22, 10, 23, 9, 24]

To generate all numbers from 0 to 1000 , one has to go to element 328002

</pre>