leetcode刷题，摸索二分法

public class Solution {
    public int SearchInsert(int[] nums, int target) {
        if (nums.Contains(target))
        {
            return Array.IndexOf(nums, target);
        }
        else
        {
            return zhong(nums,0,nums.Length-1,target);
        }
    }
    private int zhong(int[] ss,int start,int end,int target)
    {
        if (target < ss[end] && target > ss[start])
        {
            if (ss[(int)((start + end) / 2)] < target && target < ss[(int)((start + end) / 2) + 1])
            {
                return (int)((start + end) / 2) + 1;
            }
            else
            {
                if(ss[(int)((start + end) / 2)] > target)
                {
                    return zhong(ss, start, (int)((start + end) / 2),target);
                }
                else
                {
                    return zhong(ss, (int)((start + end) / 2),end , target);
                }
            }
        }
        else
        {
            if (target < ss[start])
            {
                return start;
            }
            else
            {
                return end+1;
            }
        }
    }
}

//又一版二分法
    public int half(int[] nums,int target,int start,int end){
        if(nums.Length==0){
            return 0;
        }
        else if(nums[0]>=target){
            return 0;
        }
        else if(nums[nums.Length-1]<=target){
            return nums.Length;
        }
        else{
            if(nums[(start+end)/2]<=target){
                if(nums[(start+end)/2+1]>=target){
                    return (start+end)/2+1;
                }
                else{
                    return half(nums,target,(start+end)/2,end);
                }

            }
            else{
                if((start+end)/2-1<0){
                    return 0;
                }
                else{
                    if(nums[(start+end)/2-1]<=target){
                        return (start+end)/2;
                    }
                    else{
                        return half(nums,target,start,(start+end)/2);
                    }
                }
            }
        }
    }
}

C#代码，望大神指正