《Java语言程序设计与数据结构》编程练习答案（第七章）（三）

英文名： Introduction to Java Programming and Data Structures, Comprehensive Version, 11th Edition

7.27

import java.util.Scanner;import java.util.Arrays;public class book {
       public static void main(String[] args)    {
           Scanner input = new Scanner(System.in);        System.out.print("Enter list1 size and contents: ");        int s1 = input.nextInt();        int[] l1 = new int[s1];        for(int i=0;i

7.28

这个以前有

7.29

public class book {
       public static void main(String[] args)    {
           int count = 0;        while(true)        {
               int card1 = (int)(Math.random()*52);            int card2 = (int)(Math.random()*52);            while(card2==card1)                card2=(int)(Math.random()*52);            int card3 = (int)(Math.random()*52);            while(card3==card1||card3==card2)                card3=(int)(Math.random()*52);            int card4 = (int)(Math.random()*52);            while(card4==card3||card4==card2||card4==card1)                card4=(int)(Math.random()*52);            count++;            if(card1%13+card2%13+card3%13+card4%13+4==24)                break;        }        System.out.print("There are "+count+" times.\n");    }}

7.30

import java.util.Scanner;public class book {
       public static void main(String[] args)    {
           Scanner input=new Scanner(System.in);        System.out.print("Enter thr number of values: ");        int num = input.nextInt();        System.out.print("Enter the values: ");        int[] s = new int[num];        for(int i=0;i

7.31

import java.util.Scanner;public class book {
       public static void main(String[] args)    {
           Scanner input=new Scanner(System.in);        System.out.print("Enter list1 size and contents: ");        int num1 = input.nextInt();        int[] l1  =new int[num1];        for(int i=0;i

7.32

import java.util.Scanner;public class book {
       public static void main(String[] args)    {
           Scanner input=new Scanner(System.in);        System.out.print("Enter list1 size: ");        int num1 = input.nextInt();        System.out.print("Enter list contents: ");        int[] l1  =new int[num1];        for(int i=0;i
   
    pivot)            {
                   help[ptr2]=list[i];                ptr2++;            }            else            {
                   help[ptr1]=list[i];                ptr1--;            }        }        for(int i=0;i

7.33

过于简单，

👨🐰🌶

7.34

import java.util.Scanner;import java.util.Arrays;public class book {
       public static void main(String[] args)    {
           Scanner input=new Scanner(System.in);        System.out.print("Enter a string: ");        String test = input.next();        System.out.println(sort(test));    }    public static String sort(String s)    {
           int len = s.length();        char[] ass = new char[len];        for(int i=0;i

7.35

import java.util.Scanner;import java.util.Arrays;public class book {
       public static void main(String[] args)    {
           String[] words = {
   "program","is","fun","while","damnhard","swyswyswy"};        play(words);    }    public static void play(String[] words)    {
           Scanner input = new Scanner(System.in);        char cont = 'y';        while(cont=='y')        {
               playARound(words);            System.out.print("Do you want to guess another word?Enter y or n>: ");            cont=input.next().charAt(0);            while(cont!='y'&&cont!='n')            {
                   System.out.print("Do you want to guess another word?Enter y or n>: ");                cont=input.next().charAt(0);            }        }    }    public static void playARound(String[] words)    {
           Scanner input = new Scanner(System.in);        String word = words[(int)(Math.random()*words.length)];        int len = word.length();        char[] letters = new char[len];        for(int i=0;i
   
    0)        {
               System.out.print("(Guess) Enter a letter in word "+alter(word,letters)+" > ");            char guessLetter = input.next().charAt(0);            if(belongs(guessLetter,letters))                System.out.println(guessLetter+" is already in the word");            else if(!belongs(guessLetter,word))            {
                   System.out.println(guessLetter+" is not in the word");                missCount++;            }            else            {
                   letters[lettersPointer]=guessLetter;                lettersPointer++;                notGuessed-=occurTime(guessLetter,word);            }        }        System.out.println("The word is "+word+". You missed "+missCount+" time(s)");    }    public static String alter(String word,char[] letters)    {
           String re = "";        int len = word.length();        for(int i=0;i

7.36

public class book {
       public static void main(String[] args)    {
           int[] queens = {
   0,1,2,3,4,5,6,7};        while(conflict(queens))            shake(queens);        for(int i=0;i<8;i++)        {
               for(int j=0;j
   
    1)                return true;        }        for(int i=0;i<8;i++)        {
               if(occurTime(minus[i],minus)>1)                return true;        }        return false;    }    public static int occurTime(int key, int[] set)    {
           int count=0;        for (int value : set) {
               if (key == value)                count++;        }        return count;    }}

7.37

import java.util.Scanner;import java.util.Arrays;public class book {
       public static void main(String[] args)    {
           Scanner input = new Scanner(System.in);        System.out.print("Enter the number of balls to drop: ");        int balls = input.nextInt();        System.out.print("Enter the number of slots in the bean machine: ");        int numSlot = input.nextInt();        int[] slots = new int[numSlot];        for(int i=0;i
   
    =1;i--)        {
               for(int j=0;j
    
     0.5)            {
                   bias+=0.5;                System.out.print('R');            }            else            {
                   bias-=0.5;                System.out.print('L');            }        }        System.out.print('\n');        if(numSlot%2==1)            slots[(int)(numSlot/2+bias)]++;        else        {
               if(bias>0)                slots[(int)(numSlot/2-0.5+bias)]++;            else                slots[(int)(numSlot/2+bias)]++;        }    }    public static int max(int[] ass)    {
           int max = ass[0];        for (int value : ass) {
               if (value > max)                max = value;        }        return max;    }}