实验3-方法和数组.doc

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1、 . . . . #大学计算机与信息技术学院实验报告姓 名学 号专业班级课程名称 Java实验实验日期成 绩指导教师批改日期实验名称实验3方法和数组实验目的：（1）掌握一维数组和二维数组的定义、初始化方法。（2）了解和初步应用java.lang.Math类的random（）方法处理实际问题。（3）了解增强for循环，并使用增强for循环顺序访问数组元素。（4）掌握String类中split方法、charAt方法以与length方法的使用。（5）掌握Double、Integer等数据包装类的parseDouble、parseInt等方法。（6）掌握数组的length属性的应用实验容：（要求把源程

2、序和运行结果图都粘贴到实验报告中）（1）分别用一维数组(例子数组如下 7, 4, 3, 9, 0, 6 )实现冒泡排序、选择排序和插入排序中的两种排序算法，程序中要求加注释。程序代码：1. 选择排序importjava.util.*;publicclass LX3_1 publicstaticvoid main(String args) double text= 7, 4, 3, 9, 0, 6;SelectionSort(text);publicstaticvoid SelectionSort(double list)for(int i=0;ilist.length-1;i+) /第一层循环

3、，控制拍第x数double currentMin=listi; /currentMin存储现有的最小值int currentMinIndex=i; /最小值的位置for(int j=i+1;jlistj) /如果有比他小的currentMin=listj; /吧此时的值放入currentMincurrentMinIndex=j; /记下此时的位置if(currentMinIndex !=i)listcurrentMinIndex=listi;listi=currentMin; /交换位置System.out.println(排序结果是：);for(int i=0;ilist.length;i+

4、)System.out.print( +listi); /输出已排序数组运行结果贴图：2. 插入排序importjava.util.*;publicclass LX3_2 publicstaticvoid main(String args) double text= 7, 4, 3, 9, 0, 6;insertionSort(text);publicstaticvoid insertionSort(double list)for(int i=1;i=0&listkcurrentElement;k-) listk+1=listk; /移动出插入位置listk+1=currentElement;

5、 /放入插入数据System.out.println(排序结果是：);for(int i=0;ilist.length;i+)System.out.print( +listi); /输出已排序数组运行结果贴图：3冒泡排序importjava.util.*;publicclass LX3_3 publicstaticvoid main(String args) double text= 7, 4, 3, 9, 0, 6;Sort(text);publicstaticvoid Sort(double list)for(int i=0;ii;j-) /length-1 length超出围if(lis

6、tjlistj-1)double t=listj;listj=listj-1;listj-1=t;System.out.println(排序结果是：);for(int i=0;ilist.length;i+)System.out.print( +listi); /输出已排序数组运行结果贴图:（2）编写程序实现两个矩阵的相加、相乘。要求程序运行结果形如如下显示：Array c1 2 34 5 67 8 9Array d2 2 21 1 13 3 3Array c+d3 4 55 6 710 11 12Array c*d 13 13 13 31 31 31 49 49 49程序代码：publicc

7、lass LX3_4 /* * param args */publicstaticvoid main(String args) int c = 1, 2, 3 , 4, 5, 6 , 7, 8, 9 ;int d = 2, 2, 2 , 1, 1, 1 , 3, 3, 3 ; System.out.println(Array c);shuChu(c); System.out.println(Array d);shuChu(d); System.out.println(Array c+d);Add(c,d); System.out.println(Array c*d);Cheng(c,d);/

8、TODO Auto-generated method stubpublicstaticvoid shuChu(int shuChu) for (int i = 0; i 3; i+) for (int j = 0; j 3; j+) System.out.printf(%4d,shuChuij);System.out.println();publicstaticvoid Add(int add1, int add2) int Answer = newint33;for (int i = 0; i 3; i+) for (int j = 0; j 3; j+) Answerij = add1ij

9、 + add2ij;shuChu(Answer);publicstaticvoid Cheng(int cheng1, int cheng2) int Answer = newint33;for (int i = 0; i 3; i+) for (int j = 0; j 3; j+) Answerij = cheng1i0 * cheng20j + cheng1i1* cheng21j + cheng1i2 * cheng22j;shuChu(Answer);运行结果贴图:（3）将用“；”和“，”分割的包含数字字符的字符串“23,21.3,33；34,2,1.9,2.1；3,3,1,3,4,

10、4.9”中的数据解析出来放在一个double类型的二维数组中，以分号分割二维数组的每一行，以逗号分割每行中的各个元素。（利用String 的split方法）程序代码：importjavax.swing.plaf.basic.BasicBorders.SplitPaneBorder;publicclass LX3_5 /* * param args */publicstaticvoid main(String args) String a = 23,21.3,33;34,2,1.9,2.1;3,3,1,3,4,4.9.split(;);String b = new String3;for (in

11、t i = 0; i a.length; i+) bi = ai.split(,); / 第i行的值,且split仅能放入Stringl类型double c = newdouble38;/第二个必须有围，否则无法运行for (int i = 0; i 3; i+) for (int j = 0; j bi.length; j+) cij = Double.parseDouble(bij);System.out.printf(%-8.1f,cij);System.out.println();/ TODO Auto-generated method stub运行结果贴图:（4）查看帮助、编写例子利

12、用System类中的arraycopy()方法复制数组。分别用Arrays类中的sort方法和binarySearch方法实现数组的排序和折半查找。程序代码：1. 复制数组：publicclass LX3_6 publicstaticvoid main(String args) int old = 1, 2, 3, 4, 5, 6, 7 ;int copy = newint7;System.arraycopy(old, 0, copy, 0, old.length);/ TODO Auto-generated method stubfor (int i = 0; i copy.length;

13、i+) System.out.println(copyi);运行结果贴图：2. 数组排序：import java.util.*;publicclass LX3_7 publicstaticvoid main(String args) double te = 7, 4, 3, 9, 0, 6 ;Arrays.sort(te); / 多种方法重载for (int i = 0; i te.length; i+) System.out.println(tei);运行结果贴图：3. 折半查找：import java.util.*;publicclass LX3_8 publicstaticvoid ma

14、in(String args) double te = 1, 9, 21, 31, 44, 56, 78, 99 ;System.out.println(请输入要查找的数);Scanner input = new Scanner(System.in);int i = input.nextInt();System.out.println(Arrays.binarySearch(te, i);运行结果贴图:（5）随机生成100个小写字母，统计每个字母出现的次数，并显示出来。（利用Math.random()方法随机产生）程序代码：publicclass LX3_9 publicstaticvoid

15、main(String args) char number = newchar100;for (int i = 0; i number.length; i+) numberi = (char) (a + Math.random() * (z - a + 1);CountNumber(number);publicstaticvoid CountNumber(char Count) int counts = newint26;for (int i = 0; i Count.length; i+) countsCounti - a+; /count字符减字符存到相应的位置SystemOut(coun

16、ts);publicstaticvoid SystemOut(int syso) for (int i = 0; i syso.length; i+) System.out.println(char) (i + a) + 出现的次数是： + sysoi);/i对应az运行结果贴图:（6）建立一个不规则的二维数组如下，并在控制台显示，数组如下 1 3 5 2 4 6 81 9 16 25 36 10 20 30 1 2 3 4 5 6程序代码：publicclass LX3_10 publicstaticvoid main(String args) int new1 = 1, 3, 5 , 2,

17、 4, 6, 8 , 1, 9, 16, 25, 36 , 10, 20, 30 , 1, 2, 3, 4, 5, 6 ;for (int i = 0; i 5; i+) for (int j = 0; j new1i.length; j+) System.out.printf(%-4d, new1ij);System.out.println();运行结果贴图:（7）编写两个重载的方法分别交换两个整型变量，和整型数组的第一个和第二个元素，运行并分析结果程序代码：publicclass LX3_11 publicstaticvoid main(String args) int a = 2, b

18、= 5;int c = 2, 5;Switch(a, b);Switch(c);publicstaticvoid Switch(int a, int b) int t;t = a;a = b;b = t;System.out.println(交换以后：);System.out.println(a= + a + b= + b);publicstaticvoid Switch(int a) int t;t = a0;a0 = a1;a1 = t;System.out.println(a0= + a0 + a1= + a1);运行结果贴图:课后作业题P1535.16 5.23 5.25P184 6.

19、13 P186 6.26 P202 7.1 7.2 7.6 7.23*5.16程序代码：publicclass LX3_12 publicstaticvoid main(String args) for (int i = 2000; i = 2010; i+) System.out.println(i + 年的天数是 + numberOfDaysInYear(i);publicstaticint numberOfDaysInYear(int year) if (year % 400 = 0 | (year % 4 = 0 & year % 100 != 0) return 366; else

20、return 365;运行结果贴图：5.23程序代码：publicclass LX3_13 publicstaticvoid main(String args) System.out.println(100个大写字母：);SysOut(A, Z);System.out.println(100个一位数：);SysOut(0, 9);publicstaticchar getRandomCharacter(char ch1, char ch2) return (char) (ch1 + Math.random() * (ch2 - ch1 + 1);publicstaticvoid SysOut(c

21、har zf1, char zf2) for (int i = 0; i 10; i+) for (int j = 0; j 10; j+) System.out.printf(%-4c, getRandomCharacter(zf1, zf2);System.out.println();运行结果贴图：525程序代码：import java.util.*;publicclass LX3_14 publicstaticvoid main(String args) Scanner input = new Scanner(System.in);System.out.println(请输入毫秒数：);

22、long i = input.nextLong();System.out.println(convertMillis(i);publicstatic String convertMillis(long mills) long a = mills / 3600000;long b = (mills - a * 3600000) / 60000;long c = (mills - a * 3600000 - b * 60000) / 1000;return (a + : + b + : + c); /* 转换为String类型 1.i+空或字符串; 2 String.valueOf(i);*/运行

23、结果贴图：6.13程序代码：publicclass LX3_15 publicstaticvoid main(String args) int a = 1, 4, 13, 51 ;System.out.println(getRandom(a);publicstaticint getRandom(int. numbers) int s = (int) (1 + Math.random() * 54);for (int i = 0; i numbers.length; i+) int a = numbersi - s;if (a = 0) s = getRandom(numbers);return

24、 s;运行结果贴图：6.26程序代码：import java.util.*;publicclass LX3_16 publicstaticvoid main(String args) System.out.println(Enter list1);int list1 = creatArray();System.out.println(Enter list2);int list2 = creatArray();compare(list1, list2);publicstaticint creatArray() int length = 0;Scanner input = new Scanner(

25、System.in);length = input.nextInt();int a = newintlength;for (int i = 0; i a.length; i+) ai = input.nextInt();return a;publicstaticvoid compare(int ch1, int ch2) int s = 0;if (ch1.length = ch2.length) for (int i = 0; i ch1.length; i+) s = ch1i - ch2i;if (s != 0) System.out.println(Two lists are not

26、strictly identical);System.exit(0);System.out.println(Two lists are strictly identical); elseSystem.out.println(Two lists are not strictly identical);运行结果贴图：7.1程序代码：import java.util.*;publicclass LX3_17 /* * param args */publicstaticvoid main(String args) System.out.println(Enter a 4-by-4 matrix now

27、 by row:);System.out.println(Sun of the matrix is + add(creatArrays();publicstaticint creatArrays() int array1 = newint44;Scanner input = new Scanner(System.in);for (int i = 0; i 4; i+) for (int j = 0; j 4; j+) array1ij = input.nextInt();return array1;publicstaticint add(int list) int sum = 0;for (i

28、nt i = 0; i 4; i+) for (int j = 0; j 4; j+) sum = sum + listij;return sum;运行结果贴图：7.2程序代码：import java.util.*;publicclass LX3_18 publicstaticvoid main(String args) System.out.println(Enter a 4-by-4 matrix now by row:);System.out.println(Sun of the elements in the major diagonal is + add(creatArrays();

29、publicstaticint creatArrays() int array1 = newint44;Scanner input = new Scanner(System.in);for (int i = 0; i 4; i+) for (int j = 0; j 4; j+) array1ij = input.nextInt();return array1;publicstaticint add(int list) int sum = 0;for (int i = 0; i 4; i+) for (int j = 0; j 4; j+) if (i = j) sum = sum + lis

30、tij;return sum;运行结果贴图：7.6程序代码：import java.util.Scanner;publicclass LX3_19 /* * param args */publicstaticvoid main(String args) System.out.print(Enter matrix1:);double array1 = creatArrays();System.out.print(Enter matrix2:);double array2 = creatArrays();double array3 = Cheng(array1, array2);System.ou

31、t.println(The matrices are multiplied as follows:);sysOut(array1, array2, array3);/ TODO 自动生成的方法存根publicstaticvoid sysOut(double m1, double m2, double m3) for (int i = 0; i m1.length; i+) for (int j = 0; j m1i.length; j+)System.out.printf( %2.1f, m1ij);if (i = m1.length / 2)System.out.print( + * + )

32、;elseSystem.out.print( );for (int j = 0; j m2i.length; j+)System.out.printf( %2.1f, m2ij);if (i = m1.length / 2)System.out.print( = );elseSystem.out.print( );for (int j = 0; j m3i.length; j+)System.out.printf( %-3.1f, m3ij);System.out.println();publicstaticdouble creatArrays() double array1 = newdou

33、ble33;Scanner input = new Scanner(System.in);for (int i = 0; i 3; i+) for (int j = 0; j 3; j+) array1ij = input.nextDouble();return array1;publicstaticdouble Cheng(double cheng1, double cheng2) double Answer = newdouble33;for (int i = 0; i 3; i+) for (int j = 0; j 3; j+) Answerij = cheng1i0 * cheng2

34、0j + cheng1i1* cheng21j + cheng1i2 * cheng22j;return Answer;运行结果贴图：7.23程序代码：import java.util.*;publicclass LX3_20 publicstaticvoid main(String args) double arrayText = creatArrays();double su = 1 / count1(arrayText);double arrayText2 = array2(arrayText);double arrayText3 = array3Count(arrayText2, su

35、);print(arrayText3);publicstaticdouble creatArrays() System.out.println(Enter all,a12,a13,a21,a22,a23,a31,a32,a33:);double array = newdouble33;Scanner input = new Scanner(System.in);for (int i = 0; i 3; i+) for (int j = 0; j 3; j+) arrayij = input.nextDouble();return array;publicstaticdouble count1(

36、double list) double sum = 0;sum = list00 * list11 * list22 + list20 * list01* list12 + list02 * list10 * list21- list02 * list11 * list20 - list00* list12 * list21 - list22 * list10* list01;/ sum=Math.abs(sum) ;return sum;publicstaticdouble array2(double list2) double arry2 = newdouble33;arry200 = l

37、ist211 * list222 - list212 * list221;arry201 = list202 * list221 - list201 * list222;arry202 = list201 * list212 - list202 * list211;arry210 = list212 * list220 - list210 * list222;arry211 = list200 * list222 - list202 * list220;arry212 = list202 * list210 - list200 * list212;arry220 = list210 * list221 - list211 * list220;arry221 = list201 * list