maximum-gap（经过了提示）

下面的分桶个数做的不太好，原来的解法是用的 

int gap = (big - small) / vlen;
        if (gap == 0) {
            gap = 1;
        }

下面是现在的Java解法：

package com.company;

import java.util.*;

class Solution {
    public int maximumGap(int[] nums) {
        if (nums.length < 2) {
            return 0;
        }

        // 用 Radix 排序
        int small = Integer.MAX_VALUE;
        int big = 0;
        for (int num : nums) {
            if (num < small) {
                small = num;
            }
            if (num > big) {
                big = num;
            }
        }
        System.out.println("big is " + big + " small " + small);
        int gap = (big - small - 1) / (nums.length - 1) + 1;
        if (gap == 0) {
            return 0;
        }
        int gap_num = (big - small) / gap + 1;
        int[] first = new int[gap_num];
        int[] second = new int[gap_num];
        // [ )
        System.out.println("gap is " + gap + " len is " + nums.length + "big is " + big + " small " + small);
        for (int num : nums) {
            int index = (num - small) / gap;
            if (first[index] == 0 || num < first[index]) {
                first[index] = num;
            }
            if (second[index] == 0 || num > second[index]) {
                second[index] = num;
            }
        }
        int ret = -1;
        int last = -1;
        for (int i=0; i<gap_num; i++) {
            if (first[i] == 0) {
                continue;
            }
            if (last == -1) {
                last = second[i];
                ret = last - first[i];
            }
            else {
                if (first[i] - last > ret) {
                    ret = first[i] - last;
                }
                if (second[i] - first[i] > ret) {
                    ret = second[i] - first[i];
                }
                last = second[i];
            }

        }
        return ret;
    }
}

public class Main {

    public static void main(String[] args) {
        System.out.println("Hello!");
        Solution solution = new Solution();

        int[] nums = {1,1,1,1,1,5,5,5,5,5};

        int ret = solution.maximumGap(nums);
        System.out.printf("Get ret: %s
", ret);

        /*Iterator<List<Integer>> iterator = ret.iterator();
        while (iterator.hasNext()) {
            Iterator iter = iterator.next().iterator();
            while (iter.hasNext()) {
                System.out.printf("%d,", iter.next());
            }
            System.out.println();
        }*/

        System.out.println();

    }
}