algorithms_rs/search/
binary_search.rs

1/// binary search function
2pub fn search<T>(list: &[T], item: Option<&T>) -> Option<usize>
3where
4    T: core::cmp::PartialEq + core::cmp::PartialOrd,
5{
6    let mut low = 0usize;
7    let mut high = list.len(); // or way2: let mut high = list.len() - 1
8
9    // or way2: while low <= high {
10    while low < high {
11        let mid = (low + high) / 2;
12        let guess = list.get(mid);
13        if guess == item {
14            return Some(mid);
15        } else if guess > item {
16            high = mid - 1;
17        } else {
18            low = mid + 1;
19        }
20    }
21
22    None
23}
24
25#[test]
26fn test_binary_search() {
27    let list = vec![1];
28    let idx = search(&list, Some(&1));
29    println!("idx = {idx:?}");
30}