Function binary_search

code/chapter05/exponential_search.rs:3–21

(nums: &[i32], num: i32)

// exponential_search.rs

fn binary_search(nums: &[i32], num: i32) -> bool {
    let mut low = 0;
    let mut high = nums.len() - 1;
    let mut found = false;

    // 注意是 <= 不是 <
    while low <= high && !found {
        let mid: usize = (low + high) >> 1;
        if num == nums[mid] {
            found = true;
        } else if num < nums[mid] {
            high = mid - 1;
        } else {
            low = mid + 1;
        }
    }

    found
}

fn exponential_search(nums: &[i32], target: i32) -> bool {
    let size = nums.len();