Function malachite_base::strings::exhaustive::shortlex_strings_using_chars

source · 
pub fn shortlex_strings_using_chars<I: Clone + Iterator<Item = char>>(
    cs: I,
) -> StringsFromCharVecs<ShortlexVecs<char, PrimitiveIntIncreasingRange<u64>, I>> ⓘ
Expand description

Generates [String]s with chars from a specified iterator, in shortlex order.

Shortlex order means that the [String]s are output from shortest to longest, and [String]s of the same length are output in lexicographic order with respect to the ordering of the chars specified by the input iterator.

cs must be finite; if it’s infinite, only [String]s of length 0 and 1 are ever produced.

If cs is empty, the output length is 1; otherwise, the output is infinite.

The lengths of the output [String]s grow logarithmically.

§Complexity per iteration

$T(i) = O(\log i)$

$M(i) = O(\log i)$

where $T$ is time and $M$ is additional memory.

§Examples

use itertools::Itertools;
use malachite_base::strings::exhaustive::shortlex_strings_using_chars;

let ss = shortlex_strings_using_chars('x'..='z')
    .take(20)
    .collect_vec();
assert_eq!(
    ss.iter().map(String::as_str).collect_vec().as_slice(),
    &[
        "", "x", "y", "z", "xx", "xy", "xz", "yx", "yy", "yz", "zx", "zy", "zz", "xxx", "xxy",
        "xxz", "xyx", "xyy", "xyz", "xzx"
    ]
);