LeetCodeNo.504七进制

class Solution { public String convertToBase7(int num) { if(num==0) return "0"; StringBuilder sb=new StringBuilder(); int absNum=Math.abs(num); while(absNum>0){ sb.insert(0,absNum%7);//没想到这个方法，打算用reverse()的 absNum/=7; } return num>0?sb.toString():"-"+sb.toString(); } }