桶排序、 计数排序、 基数排序 && 排序后邻数最大差值

    public static int maxGap(int[] nums) {
        if (nums == null && nums.length<2){
            return 0;
        }
        int min = Integer.MAX_VALUE;
        int max = Integer.MIN_VALUE;
        for (int i = 0; i < nums.length;i++){
            min = Math.min(nums[i],min);
            max = Math.max(nums[i],max);
        }
        if (min == max) return 0;
        int [] maxs = new int[nums.length+1];
        int [] mins = new int[nums.length+1];
        boolean[] hasNum = new boolean[nums.length+1];
        for (int i = 0 ; i < nums.length ;i++){
            int bid = bucket(nums[i],nums.length,min,max);
            maxs[bid] = hasNum[bid] ? Math.max(maxs[bid],nums[i]):nums[i];
            mins[bid] = hasNum[bid] ? Math.min(mins[bid],nums[i]):nums[i];
            hasNum[bid] = true;
        }
        int lastMax = maxs[0];
        int res = 0;
        for (int i = 1;i<= nums.length ;i++){
            if (hasNum[i]){
                res = Math.max(res,mins[i] - lastMax);
                lastMax = maxs[i];
            }
        }
        return res;
    }

    public static int bucket(long num, long len, long min, long max) {
        return (int) ((num - min) * len / (max - min));
    }