搜狗网申的java笔试题！该如何处理

public class Test {    public static void encode(byte[] in, byte[] out, int password) {    int len = in.length;    int seed = password ^ 0x36a67d8d;    for (int i = 0; i < len; ++i) {        byte a = (byte) ((in[i] ^ seed) >>> 4);        byte b = (byte) (((((int) in[i]) << 11) ^ seed) >>> (11 - 4));        a &= 0xf;        b &= 0xf0;        out[i] = (byte) (a | b);        seed = (((seed << 7) ^ seed ^ out[i]) + 536513);    }    }    public static void decode(byte[] in, byte[] out, int password) {    int len = in.length;    int seed = password ^ 0x36a67d8d;    for (int i = 0; i < len; ++i) {        // fill the code here          //--------------------------------------------------------        //想办法循环左移4位        byte a = (byte) ((in[i]) << 4); ////有效位剩余4位        byte b = (byte) ((in[i]) >>> 4); // //有效位剩余4位        //---------------------------------------------------------        a = (byte) (a ^ seed); // 还原        a &= 0xf0; //无效位再次置0，因为有可能，经过异或之后变成1了        b = (byte) (((((int) b) << 11) ^ seed) >>> 11); // 还原        b &= 0x0f; ////无效位再次置0，因为有可能，经过异或之后变成1了         //System.out.println(out[i]);        out[i] = (byte) (a | b); //将临时变量中的数据串接，保存到out[i],这是真实的数据来了，        //每一次循环seed是不一样的，利用输入数据in[i]和常量536513求出seed        // System.out.println(out[i]);        seed = (((seed << 7) ^ seed ^ in[i]) + 536513);    }    }    public static void main(String[] args) throws Exception {    int password = 0xcd2c0597;    byte[] buf1 = { 77, 92, 43, 109, 120, -102, 97, 127, -105, -104, 47,        67, -2, 12, -89, -57, -125, -65, -7, -55, 123, 97, -99, -76,        -127, -44, 66, -77, -115, 89, 118, -17, 64, 32, -58, 54, 121,        -54, -78, 77, -70, -51, };    byte[] buf2 = new byte[buf1.length];    decode(buf1, buf2, password);    System.out.println(new String(buf2, "GBK"));    }}/*output搜狗手机输入法为亿万手机用户负责！！！！！*/