题解 | #二分查找-I#

using System;
using System.Collections.Generic;


class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param nums int整型一维数组
     * @param target int整型
     * @return int整型
     */
    public int recurison(List<int> nums, int left, int right, int target) {
        int mid = (left + right) / 2;
        if (left > right) return -1;
        if (target < nums[mid]) {
            return recurison(nums, left, mid - 1, target);
        } else if (target > nums[mid]) {
            return  recurison(nums, mid + 1, right, target);
        } else if (target == nums[mid]) {
            return mid;
        }
        return nums[mid];
    }
    public int search(List<int> nums, int target) {
        // write code here
        if (nums.Count == 0) return -1;
        return recurison(nums, 0, nums.Count - 1, target);
    }

}