Function malachite_base::iterators::comparison::is_weakly_zigzagging

pub fn is_weakly_zigzagging<I: Iterator>(xs: I) -> bool
where
    I::Item: Ord,

Determines whether the sequence weakly zigzags.

A weakly zigzagging sequence is one where every odd-indexed element is greater than or equal to its even-indexed neighbors, or one where every odd-indexed element is less than or equal to its even-indexed neighbors.

This function will hang if given an infinite strictly zigzagging iterator.

Examples

use malachite_base::iterators::comparison::is_weakly_zigzagging;

assert_eq!(is_weakly_zigzagging([1, 2, 3, 4].into_iter()), false);
assert_eq!(is_weakly_zigzagging([4, 3, 2, 1].into_iter()), false);
assert_eq!(is_weakly_zigzagging([1, 3, 2, 4].into_iter()), true);
assert_eq!(is_weakly_zigzagging([1, 2, 2, 4].into_iter()), true);