第一次寫部落格,有不足之處還請大家多指正

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int num = scanner.nextInt();
		String[] ss = new String[num];
		for (int i = 0; i < ss.length; i++) {
			ss[i] = scanner.next();
		}
		scanner.close();
		for (String string : ss) {
			System.out.println(binToOct(hexToBin(string)));
		}
	}

	private static String hexToBin(String value) { // value:單個十六進位制數的字串
		char[] c = value.toCharArray();
		StringBuffer stringBuffer = new StringBuffer();
		for (int i = 0; i < c.length; i++) {
			stringBuffer.append(toBinTable(c[i]));
		}
		return stringBuffer.toString();
	}


	// 二進位制轉八進位制時 三對一 有三種情況,但當value.length()%3==0時無需補0

	private static String binToOct(String value) { // value:單個二進位制數的字串
		StringBuffer stringBuffer = new StringBuffer();
		if (value.length() % 3 == 1) {
			value = "00" + value;
		} else if (value.length() % 3 == 2) {
			value = "0" + value;
		}

		for (int i = 0; i < value.length(); i += 3) {
			String temp = value.substring(i, i + 3);
			stringBuffer.append(ToOtcTable(temp));
		}
		// 刪除八進位制數前面多餘的0
		char[] c = stringBuffer.toString().toCharArray();
		for (int i = 0; i < 2; i++) {
			if (c[i] == '0') {
				stringBuffer.delete(i, i + 1);
			}
		}
		return stringBuffer.toString();
	}

	static String toBinTable(char c) {
		StringBuffer stb = new StringBuffer();
		switch (c) {
		case '0':stb.append("0000");break;
		case '1':stb.append("0001");break;
		case '2':stb.append("0010");break;
		case '3':stb.append("0011");break;
		case '4':stb.append("0100");break;
		case '5':stb.append("0101");break;
		case '6':stb.append("0110");break;
		case '7':stb.append("0111");break;
		
		case '8':stb.append("1000");break;
		case '9':stb.append("1001");break;
		case 'A':stb.append("1010");break;
		case 'B':stb.append("1011");break;
		case 'C':stb.append("1100");break;
		case 'D':stb.append("1101");break;
		case 'E':stb.append("1110");break;
		case 'F':stb.append("1111");break;
		
		default:break;
		}
		return stb.toString();

	}

	static String ToOtcTable(String value) {
		StringBuffer stb = new StringBuffer();
		switch (value) {
		case "000":stb.append("0");break;
		case "001":stb.append("1");break;
		case "010":stb.append("2");break;
		case "011":stb.append("3");break;
		case "100":stb.append("4");break;
		case "101":stb.append("5");break;
		case "110":stb.append("6");break;
		case "111":stb.append("7");break;

		default:break;
		}
		return stb.toString();

	}
}