Function linear_search 

pub fn linear_search<T>(arr: &[T], target: &T) -> Option<usize>
where
    T: PartialEq,

线性搜索/Linear search

参数/Arguments

• arr - 要搜索的数组/The array to search
• target - 要查找的目标/The target to find

返回值/Returns

目标索引（如果找到）/Index of target if found

示例/Examples

use slice_reducer::linear_search;
let arr = [10, 20, 30];
assert_eq!(linear_search(&arr, &20), Some(1));
assert_eq!(linear_search(&arr, &40), None);