class Solution {
    public int searchInsert(int[] nums, int target) {
if(nums==null&&nums.length==0)
{
    return 0;
}
int l=0;
int r=nums.length-1;
while(l<r)
{
    int mid=l+(r-l)/2;
    if(nums[mid]==target)
    {
        return mid;
    }
   else if(nums[mid]>target)
   {
       r=mid;
   }
   else {
       l=mid+1;
   }
}
return nums[l]<target?l+1:l;
    }
}

二分法