a736933735的专栏

import java.util.*;/** 通过该类对象调用ChangToBit(char c)方法可返回2进制表示的字符串*/class Hexadecimal{ String[] hex={ "0000","0001","0010","0011","0100","0101","0110","0111", "1000","1001","1010","1011","1100","1101","1110","1111" }; public String ChangeToBit(char c){ if(c>=’0’&&c<=’9′){ return hex[c-‘0’]; } else return hex[c-‘A’+10]; } } /** 通过调用该类对象的changeToOex(String astring)方法可返回该3位2进制串的8进制数值*/class Oex{ String[] oex={ "000","001","010","011","100","101","110","111" }; public int changeToOex(String astring){ for(int i=0;i<8;i++){ if(oex[i].equals(astring)==true){ return i; } } return 0; } } public class 十六进制转八进制 { //将aString的位数在字符串开头补全为3的倍数，，返回补全后的字符串static Hexadecimal hex=new Hexadecimal(); static Oex oex=new Oex(); public static String BuQuanSanWei(String aString){ String ret=""; if(aString.length()%3==0)return aString; if((aString.length()+1)%3==0){ ret+="0"; ret+=aString; return ret; } ret+="00"; ret+=aString; return ret; } //必须用StringBuilder建立2进制字符串，否则由于需建立的字符太长会超时 public static void main(String[] args) { Scanner in=new Scanner(System.in); int N=in.nextInt(); while(N–!=0){ String aString=in.next(); StringBuilder bitStringbuilder=new StringBuilder(); for(int i=0;i<aString.length();i++){ bitStringbuilder.append(hex.ChangeToBit(aString.charAt(i))); } String bitString=BuQuanSanWei(bitStringbuilder.toString()); //补全位数为3的倍数int hasOut=0; //标记是否有输出for(int i=0;i<bitString.length()-2;i+=3){ String nowCun=""; nowCun+=bitString.charAt(i); nowCun+=bitString.charAt(i+1); nowCun+=bitString.charAt(i+2); int Num=oex.changeToOex(nowCun); if(i==0&&Num==0) continue; hasOut=1; System.out.print(Num); } if(hasOut==0)System.out.print("0"); System.out.println(); } } }

敏而好学，不耻下问。