36 进制加法 Java 极简实现

    //62进制，62位字符串
	// private static final String chars =
	// "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	private static final String chars = "0123456789abcdefghijklmnopqrstuvwxyz";

	public static void main(String[] args) {
		System.out.println(add_36("xx", "oo"));
	}

	/**
	 * 123+abcd
	 * 
	 * @param a
	 * @param b
	 * @return
	 */
	public static String add_36(String a, String b) {
		int alength = a.length();
		int blength = b.length();
		int m = Math.max(alength, blength);
		int inc = 0;
		int clength = chars.length();
		String result = "";
		for (int i = 0; i < m; i++) {
			int ia = i < alength ? chars.indexOf(a.charAt(alength - i - 1)) : 0;
			int ib = i < blength ? chars.indexOf(b.charAt(blength - i - 1)) : 0;
			int add = ia + ib + inc;
			if (add > clength) {
				inc = add / clength;
			}
			result = chars.charAt(add % clength) + result;
		}
		if (inc > 0) {
			result = chars.charAt(inc) + result;
		}

		return result;
	}