Find First and Last Position of

如题，要求找到target所在位置的最大和最小值
题中nums为顺序增序，要求查找时间为o(logn)，那么考虑用二分法，先随机找到一个，然后左右扩增
代码如下

public class searchRange {
    public static int[] searchRange(int[] nums, int target) {
        int a = search(nums,0, nums.length-1, target);
        int[] r = new int[2];
        r[0]=a;
        r[1]=a;
        if(a==-1)return r;
        int i=a;
        while(nums[i]==target){
            r[0]=i;
            i--;
            if(i<0)break;
        }
        i=a;
        while(nums[i]==target){
            r[1]=i;
            i++;
            if(i>=nums.length)break;
        }
        return r;
    }

    public static int search(int[] nums, int left, int right, int target){
        if(left>right)return -1;
        int middle = (left+right)/2;
        if(nums[middle]>target){
            return search(nums, left,middle-1,target);
        }else if(nums[middle]<target){
            return search(nums, middle+1,right,target);
        }else {
            return middle;
        }
     }

    public static void main(String[] args) {
        int[] a = {1};
        int[] r = searchRange(a,1);
        System.out.println(r[0]);
        System.out.println(r[1]);
    }
}