递归方法解决二分查找

**import java.util.*;

public class Solution {

public int search (int[] nums, int target) {
return search1(nums,0,nums.length-1,target);

}public static int search1(int[] nums,int left,int right ,int target){ if(left>right){ return -1; } int mid=(left+right)/2; int midval=nums[mid]; if(midvaltarget){ return search1(nums,left,mid-1,target); }else {//这里就是nums[mid]==target while(mid >= 1 && nums[mid-1] == target ){ mid--; }//这里mid必须大于1得原因是防止nums[mid-1]<0 return mid; }}

}**