Leetcode128. 最长连续序列

题目传送： https://leetcode.cn/problems/longest-consecutive-sequence/submissions/

运行效率：

代码如下：

 public int longestConsecutive(int[] nums) {
        //处理边界情况
        if(nums.length==0){
            return  0;
        }
        Arrays.sort(nums);
        int result = 1;
        int left = 0;
        int right = 0;
        while (right < nums.length - 1) {
            //如果是连续的，那就右指针一直往后移动
            if (nums[right]== nums[right + 1] ||nums[right] + 1 == nums[right + 1]) {
                right++;
                //如果已经移动到数组的边界了
                if(right==nums.length-1){
                    int length = getLength(nums, left, right);
                    result = Math.max(length, result);
                }
            }else{
                int length = getLength(nums, left, right);
                result = Math.max(length, result);
                left=right+1;
                right=left;
            }
        }
        return result;
    }

    /**
     *  查询left到right位置之间所有不重复元素的个数
     * @param nums
     * @param left
     * @param right
     * @return
     */
    public int getLength(int[] nums,int left,int right){
        HashSet<Integer> set = new HashSet<>();
        for(int i=left;i<=right;i++){
            set.add(nums[i]);
        }
        return  set.size();
    }
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