解决思路

二分查找

  //left表示是否为寻找左边坐标
    private int extremeInsertionIndex(int[] nums,int target,boolean left){
        int l = 0;
        int r = nums.length;
        //二分法
        while (l < r){
            int mid = (l + r) / 2;
            if (nums[mid] > target || (left && target == nums[mid]))
                r = mid;
            else
                l = mid + 1;
        }
        return l;
    }
   public int[] searchRange(int[] nums,int target){
       int[] targetRange = {-1,-1};
       //先寻找左边的坐标
       int leftIdx = extremeInsertionIndex(nums,target,true);
       if (leftIdx == nums.length || nums[leftIdx] != target)
           return targetRange;
       targetRange[0] = leftIdx;
       //再寻找有右边的坐标
       targetRange[1] = extremeInsertionIndex(nums,target,false)-1;
       return targetRange;
   }