算法题之端口（2017百度实习笔试题）

import com.sun.deploy.util.StringUtils;

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int isComprise = scanner.nextInt();
        String line = scanner.next();
        /*int isComprise = 1;
        String line = "1011:110011:101101:";*/

        String result;
        if (isComprise == 0) {
            // 001011:110011:101101:000000
            // 1011:110011:101101:
            String[] group = line.split(":");
            for (int j=0; j<group.length; j++) {
                if (group[j].contains("1")) group[j] = group[j].substring(group[j].indexOf("1"));
                else group[j] = " ";
            }
            result = StringUtils.join(Arrays.asList(group), ":").replace(" ", "");
        } else {
            // 1011:110011:101101:
            // 001011:110011:101101:000000
            if (line.charAt(line.length()-1) == ‘:‘) line += " ";
            String[] group = line.split(":");
            for (int j=0; j<group.length; j++) {
                if (group[j].equals(" ")) group[j] = "0";
                StringBuilder sb = new StringBuilder();
                for (int i=0; i<6-group[j].length(); i++)
                    sb.append("0");
                group[j] = sb.append(group[j]).toString();
            }
            result = StringUtils.join(Arrays.asList(group), ":");
        }
        System.out.println(result);
    }
}