微软2014实习生及秋令营技术类职位在线测试:String reorder

import java.util.Scanner;public class Stringreorder {/** * @param args */public static void main(String[] args) {int len = 36 ;int num[] = new int[len] ;char charset[]={'0','1','2','3','4','5','6','7','8','9',        'a','b','c','d','e','f','g','h','i','j',        'k','l','m','n','o','p','q','r','s','t',        'u','v','w','x','y','z'};Scanner in = new Scanner(System.in);while(in.hasNext()){for(int k = 0 ;k < len ;k++)num[k] = 0 ;boolean flat = false ;String input = in.nextLine();int length  = input.length();for(int i = 0 ; i < length ; i++){char ch = input.charAt(i);if(ch >='0' && ch <= '9')num[ch-'0']++;else if (ch >='a' && ch <='z')num[ch-'a' +10]++;else {  flat =true;  break ;}}if(flat){System.out.println("<invalid input string>");continue;}int i = 0 ;while(length >0){if(i > 35) i %=36 ;if(num[i] > 0){System.out.print(charset[i]);num[i]--;length--;}i++;}System.out.println();}}}