Integer将对应的字符串转为对应的十进制
Integer.parseInt(str,radix);将字符串转为对应的进制
将对应的二进制数转为对应的字符串
Integer.toBinaryString()

正整数比较大小 Intege.compare(int a,int b);
字符串比较大小 str1.compareTo(String a);

通过缓冲字符流加快输入输出
BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));
BufferedWriter writer=new BufferedWriter(new OutputStreamWriter(System.out));
int t=Integer.parseInt(reader.readLine());
writer.write(Integer.toString(t));
writer.newLine();
writer.flush();