Given an integer, return its base 7 string representation.
Example 1:
Input: 100 Output: "202"Example 2:
Input: -7 Output: "-10"Note: The input will be in range of [-1e7, 1e7].
public class demo1 { public String convertToBase7(int num) { String result=""; if(num==0) result="0"; int number=Math.abs(num); while (number>0) { int b=number%7; number=number/7; result=String.valueOf(b)+result; } if(num<0) { result="-"+result; } return result; } public static void main(String[] args){ int num=-7; demo1 r = new demo1(); System.out.println(r.convertToBase7(num)); } } 提交答案后，看到leetcode讨论区中的一个答案，只有五行，递归，简单到爆，特地copy过来膜拜膜拜。 public String convertToBase7(int num) { if (num < 0) return '-' + convertToBase7(-num); if (num < 7) return num + ""; return convertToBase7(num / 7) + num % 7; }
