leetcode 33 rust

题目

编程语言

rust

注意点

二分法

代码

pub fn search(nums: Vec<i32>, target: i32) -> i32 {
    let mut left = 0_i32;
    let mut right = (nums.len() as i32) - 1;
    let mut mid;
    while left <= right {
        mid = left + ((right - left) >> 1);
        if nums[mid as usize] == target {
            return mid as i32;
        }
        match nums[mid as usize].cmp(&nums[left as usize]) {
            // left和mid 落在同一数组中
            std::cmp::Ordering::Greater | std::cmp::Ordering::Equal => {
                // left，mid，right，target在同一数组中
                if nums[mid as usize] > target && target >= nums[left as usize] {
                    right = mid - 1;
                // target落在mid和right中间
                }else if nums[mid as usize] < target || target < nums[left as usize] {
                    left = mid + 1;
                }
            },
            // left和mid 落在两个数组中
            std::cmp::Ordering::Less => {
                // left，mid，right，target在同一数组中
                if nums[mid as usize] < target && target <= nums[right as usize] {
                    left = mid + 1;
                // target落在left和mid中间
                }else if nums[mid as usize] > target || target > nums[right as usize] {
                    right = mid - 1;
                }
            },
        }
    }
    -1
}

测试

#[cfg(test)]
mod tests{
    use super::*;
    #[test]
    fn test_exist(){
        assert_eq!(search(vec![4,5,6,7,0,1,2],0),4);
    }
    #[test]
    fn test_not_exist1(){
        assert_eq!(search(vec![4,5,6,7,0,1,2],3),-1);
    }
    #[test]
    fn test_not_exist2(){
        assert_eq!(search(vec![1],0),-1);
    }
}