第八次作业
1.编写一个简单程序,要求数组长度为5,分别赋值10,20,30,40,50,在控制台输出该数组的值。(知识点:数组定义和创建、一维数组初始化)[必做题]?
import java.util.Scanner; public class xyxy { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); int a[] = new int[5]; for (int i = 0; i < a.length; i++) { a[i] = input.nextInt(); } } }
2.将一个字符数组的值(neusofteducation)拷贝到另一个字符数组中。(知识点:数组复制) [必做题]?
import java.util.Scanner; public class xyxy { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); String a[] = {"neusofteducation"}; String b[] =new String [a.length]; System.arraycopy(a, 0, b, 0, a.length); for (String i : b) { System.out.println(i); } } }
3. 给定一个有9个整数(1,6,2,3,9,4,5,7,8)的数组,先排序,然后输出排序后的数组的值。(知识点:Arrays.sort排序、冒泡排序)
import java.util.Scanner; public class xyxy { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = { 1, 6, 2, 3, 9, 4, 5, 7, 8 }; int c; for (int i = 0; i < a.length - 1; i++) { for (int j = 0; j < a.length - 1 - i; j++) { if (a[j] > a[j + 1]) { c = a[j]; a[j] = a[j + 1]; a[j + 1] = c; } } } for (int i : a) { System.out.println(i); } } }
package yyy; import java.util.Arrays; import java.util.Scanner; public class yyyy { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = { 1, 6, 2, 3, 9, 4, 5, 7, 8 }; Arrays.sort(a); for (int i : a) { System.out.println(i); } } }
4.输出一个double型二维数组(长度分别为5、4,值自己设定)的值。(知识点:数组定义和创建、多维数组初始化、数组遍历)
package yyy; import java.util.Scanner; public class yyyy { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double a[][]=new double[4][5]; for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[i].length; j++) { a[i][j]=i; } } for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[i].length; j++) { System.out.print(a[i][j]+" "); } System.out.println(); } } }
5.在一个有8个整数(18,25,7,36,13,2,89,63)的数组中找出其中最大的数及其下标。(知识点:数组遍历、数组元素访问) [必做题]?
package yyy; import java.util.Arrays; import java.util.Scanner; public class yyyy { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = new int[] { 18, 25, 7, 36, 13, 2, 89, 63 }; int max; int s=0; max = a[0]; for (int i = 0; i < a.length; i++) { if (max < a[i]) { max = a[i]; s=i; } } System.out.println(max); System.out.println(s); } }
6、将一个数组中的元素逆序存放(知识点:数组遍历、数组元素访问)
package ggg; import java.util.Scanner; public class yyyy { public static void main(String[] args) { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); System.out.println("请输入数组中元素个数:" ); int x=input.nextInt(); int a[] = new int[x]; System.out.println("请输入数组元素:"); for (int i = 0; i < x; i++) { a[i] = input.nextInt(); } System.out.println("逆序存放:"); for (int j = x - 1; j > 0; j--) { System.out.print(a[j]); } System.out.println(a[0]); } }
7. 将一个数组中的重复元素保留一个其他的清零。(知识点:数组遍历、数组元素访问)
package ggg; import java.util.Scanner; public class yyyy { public static void main(String[] args) { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); System.out.println("请输入数组中元素个数:" ); int x=input.nextInt(); int a[]=new int[x]; System.out.println("请输入数组元素:" ); for (int i = 0; i < x; i++) { a[i]=input.nextInt(); } System.out.println("整理后:" ); for (int m = 0; m < a.length; m++) { for (int n = m+1; n < a.length; n++) { if(a[m]==a[n]) { a[n]=0; } } System.out.print(a[m] ); } } }
8、给定一维数组{ -10,2,3,246,-100,0,5},计算出数组中的平均值、最大值、最小值。(知识点:数组遍历、数组元素访问)
package ggg; import java.util.Arrays; import java.util.Scanner; public class yyyy { public static void main(String[] args) { // TODO Auto-generated method stub int []a={ -10,2,3,246,-100,0,5}; Arrays.sort(a); System.out.println("最大值"+a[a.length-1]); System.out.println("最小值"+a[0]); double sum=0.0; for(int i=0;i<a.length;i++) { sum+=a[i]; } System.out.println("数组的平均值是"+sum/a.length); } }
9、使用数组存放裴波那契数列的前20项 ,并输出 1 1 2 3 5 8 13 21
package ggg; import java.util.Arrays; import java.util.Scanner; public class yyyy { public static void main(String[] args) { // TODO Auto-generated method stub int []a = new int[20]; a[0] = 1; a[1] = 1; for (int i = 2; i < a.length; i++) { a[i]=a[i-1]+a[i-2]; } for (int i = 0; i < 8; i++) { System.out.print(a[i]+" "); } } }
10、生成一个长度为10的随机整数数组(每个数都是0-100之间),输出,排序后,再输出
package ggg; import java.util.Arrays; import java.util.Random; import java.util.Scanner; public class yyyy { public static void main(String[] args) { // TODO Auto-generated method stub int a[]=new int[10]; Random r=new Random(); for (int i = 0; i < a.length; i++) { a[i]=r.nextInt(101); } for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } System.out.println("排序后:"); Arrays.sort(a); for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } }