华为手撕代码：数组转最大整数

题目描述：

给定一个正整数数组，返回该数组能够拼接成的最大整数，不可拆分数组中的数字

例如：

数组[3,30,34,5,9]能够组成的最大整数为9534330

数组[10,101011,34,5,9]能够组成的最大整数为953410101110

解析：

☆要点一：要实现一个字符串比较器

☆要点二：要实现递归比较，以应对3vs30、10vs101011这种情况

代码实现：

 1 package com.test.od;
 2 
 3 import java.util.Arrays;
 4 import java.util.Comparator;
 5 
 6 public class OD3 {
 7     // 10110 10
 8     public static String generateMaxNum(int[] nums){
 9         String[] numsStr = new String[nums.length];
10         for (int i = 0; i < nums.length; i++){
11             numsStr[i] = String.valueOf(nums[i]);
12         }
13         Arrays.sort(numsStr, new Comparator<String>() {
14             @Override
15             public int compare(String o1, String o2) {
16                 int minLen = Math.min(o1.length(), o2.length());
17                 int maxLen = Math.max(o1.length(), o2.length());
18                 // 递归次数
19                 int times = maxLen / minLen + 1;
20                 // 把较短的字符串自我复制times次以递归比较
21                 if (o1.length() < o2.length()){
22                     StringBuilder builder = new StringBuilder();
23                     for (int i = 0; i < times; i++){
24                         builder.append(o1);
25                     }
26                     o1 = builder.toString().substring(0, maxLen);
27                 }else {
28                     StringBuilder builder = new StringBuilder();
29                     for (int i = 0; i < times; i++){
30                         builder.append(o2);
31                     }
32                     o2 = builder.toString().substring(0, maxLen);
33                 }
34                 // 处理后的两字符串长度相等，开始倒序比较
35                 for (int i = 0; i < maxLen; i++){
36                     if (o1.charAt(i) > o2.charAt(i)){
37                         return -1;
38                     }else if (o1.charAt(i) < o2.charAt(i)){
39                         return 1;
40                     }
41                 }
42                 return 0;
43             }
44         });
45         StringBuilder resBuilder = new StringBuilder();
46         for (String numStr : numsStr){
47             resBuilder.append(numStr);
48         }
49         return resBuilder.toString();
50     }
51 
52     public static void main(String[] args) {
53 //        int[] nums = {3,30,34,5,9};
54         int[] nums = {10,101011,34,5,9};
55         System.out.println(generateMaxNum(nums));
56     }
57 }

标签：String,nums,int,length,整数,华为,数组,o2,o1
来源： https://www.cnblogs.com/WinterRain/p/16120812.html