快手：笔试题（版本号比较，平方和为1，合并两个流）

1. 版本号比较

方法1，没有AC

public class A19 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        sc.nextLine();
        String[][] strs = new String[m][2];
        boolean[] result = new boolean[m];
        for (int i = 0; i < m; i++) {
            strs[i] = sc.nextLine().split(" ");
            int c1 = strs[i][0].split("\.").length;
            int c2 = strs[i][1].split("\.").length;
            while(c1<c2){
                strs[i][0]+=".0";
                c1++;
            }
            while(c1>c2){
                strs[i][1]+=".0";
                c2++;
            }
            if(strs[i][0].compareTo(strs[i][1])<0){
                result[i]= true;
            }
        }
        for (int i = 0; i < m; i++) {
            System.out.println(result[i]);
        }
    }
}

方法2 没有ac

package test;

import java.util.Scanner;

public class A17 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        sc.nextLine();
        String[][] strs = new String[m][2];
        
        for (int i = 0; i < m; i++) {
            strs[i] = sc.nextLine().split(" ");
        }
        boolean[] result = new boolean[m];
        for (int i = 0; i < m; i++) {
            String[] str1 = strs[i][0].split("\.");
            String[] str2 = strs[i][1].split("\.");
            int[] val1 = new int[4];
            int[] val2 = new int[4];
            for (int j = 0; j < str1.length; j++) {
                val1[j] = Integer.valueOf(str1[j]);
            }
            for (int j = 0; j < str2.length; j++) {
                val2[j] = Integer.valueOf(str2[j]);
            }
            for (int j = 0; j < 4; j++) {
                if(val1[j]<val2[j]){
                    result[i]=true;
                    break;
                }
            }
        }
        for (int i = 0; i < m; i++) {
            System.out.println(result[i]);
        }
    }
}

方法3 AC

作者：jerryzhuo
链接：https://www.nowcoder.com/discuss/233405?type=post&order=time&pos=&page=1
来源：牛客网

import java.util.Scanner;
 
/**
 * 版本问题
 */
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int m = in.nextInt();
        String[] op1 = new String[m];
        String[] op2 = new String[m];
        for (int i = 0; i < m; i++) {
            op1[i] = in.next();
            op2[i] = in.next();
        }
 
        Main main = new Main();
        main.outputResult(op1, op2);
    }
 
    private void outputResult(String[] op1, String[] op2) {
        boolean[] result = new boolean[op1.length];
        for (int i = 0; i < op1.length; i++) {
            String[] oneArray = op1[i].trim().split("\.");
            String[] twoArray = op2[i].trim().split("\.");
            boolean isOk = true;
 
            int pointerOne = 0;
            int pointerTwo = 0;
            while (pointerOne < oneArray.length && pointerTwo < twoArray.length) {
                int compare = Integer.parseInt(oneArray[pointerOne]) - Integer.parseInt(twoArray[pointerTwo]);
                if (compare < 0) {
                    break;
                } else if (compare > 0) {
                    isOk = false;
                    break;
                } else if (pointerOne == oneArray.length - 1) {
                    pointerTwo++;
                    while (pointerTwo < twoArray.length && twoArray[pointerTwo].equals("0")) {
                        pointerTwo++;
                    }
                    if (pointerTwo == twoArray.length) {
                        isOk = false;
                    }
                } else if (pointerTwo == twoArray.length - 1) {
                    isOk = false;
                    break;
                }
                pointerOne++;
                pointerTwo++;
            }
 
            result[i] = isOk;
        }
 
        for (boolean value : result) {
            System.out.println(value);
        }
    }
}

2. 平方和为1

4 → 16 → 37 → 58 → 89 → 145 → 42 → 20 → 4 ，循环了，return false

AC

方法1

import java.util.Scanner;

public class A20 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        int[] n = new int[m];
        for (int i = 0; i < m; i++) {
            n[i] = sc.nextInt();
            
        }
        for (int i = 0; i < m; i++) {
            long result = getresult(n[i]);
            boolean r = true;
            while(result!=1){
                result = getresult(result);
                if(result==n[i]){
                    r=false;
                    break;
                }
            }
            System.out.println(r);
        }
        
    }
    public static long getresult(long result2){
        long result = 0;
        
        while(result2!=0){
            long digit = result2 % 10;
            result = result+ digit*digit;
            result2 = result2/10;
        }
        return result;
    }
}

方法2

import java.util.Scanner;

public class A20 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        int[] n = new int[m];
        for (int i = 0; i < m; i++) {
            n[i] = sc.nextInt();
            
        }
        for (int i = 0; i < m; i++) {
            long result = getresult(n[i]);
            int time =0;
            while(result!=1 && time<1000){
                result = getresult(result);
                time++;
            }
            if(result==1){
                System.out.println(true);
            }else{
                System.out.println(false);
            }
        }
        
    }
    public static long getresult(long result2){
        long result = 0;
        
        while(result2!=0){
            long digit = result2 % 10;
            result = result+ digit*digit;
            result2 = result2/10;
        }
        return result;
    }
}

3. 合并两个流

AC 

import java.util.Scanner;

public class A18 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] str1 = sc.nextLine().split(" ");
        String[] str2 = sc.nextLine().split(" ");
        int len1 = str1.length;
        int len2 = str2.length;
        String[] result = new String[len1+len2];
        int position = 0;
        int index2 = 0;
        for (int i = 0; i < len1; i++) {
            if((i+1)%4==0 && index2<len2){
                result[position++]=str1[i];
                result[position++]=str2[index2++];
            }else{
                result[position++]=str1[i];
            }
        }
        while(index2<len2){
            result[position++]=str2[index2++];
        }
        
        for (int i = 0; i < (len1+len2); i++) {
            System.out.print(result[i]);
            if(i!=(len1+len2-1)){
                System.out.print(" ");
            }
        }
    }
}