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.
package aaa;
import java.util.Scanner;
public class A {
/**
* @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();
}
for (int j = 0; j < a.length; j++) {
System.out.println(a[j]);
}
}
}
2、将一个字符数组的值(neusofteducation)拷贝到另一个字符数组中。
package aaa;
import java.util.Scanner;
public class B {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("将字符的值拷贝到另一个数组");
String[] x = new String[7];
String[] y = new String[x.length];
Scanner input = new Scanner(System.in);
for (int i = 0; i < x.length; i++) {
x[i] = input.next();
}
for (int i = 0; i < x.length; i++) {
y[i] = x[i];
}
for (int j = 0; j < y.length; j++) {
System.out.println(y[j]);
}
}
}
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。
package aaa;
public class C {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[] = new int[] { 1, 6, 2, 3, 9, 4, 5, 7, 8 };
for (int i = 0; i < a.length - 1; i++) {
for (int j = 0; j < a.length - 1; j++) {
if (a[j] > a[j + 1]) {
int x = a[j];
a[j] = a[j + 1];
a[j + 1] = x;
}
}
}
for (int i = 0; i < a.length - 1; i++) {
System.out.println(a[i]);
}
}
}
package aaa;
import java.util.Arrays;
public class D {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[] = new int[] { 1, 6, 2, 3, 9, 4, 5, 7, 8 };
Arrays.sort(a);
for (int i = 0; i < a.length; i++) {
System.out.println(a[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 aaa;
public class E {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
double a[][] = new double[5][4];
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.println(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 aaa;
public class E {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[]={18,25,7,36,13,2,89,63};
int max=a[0];
int x=-1;
for (int i = 0; i < a.length; i++) {
if(a[i]>max){
max=a[i];
}
x++;
}
System.out.println("最大值"+max);
System.out.println("下表为"+x);
}
}
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) [选作题]•
package aaa;
public class E {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[]={18,25,7,36,13,2,89,63};
System.out.println("倒序后为:");
for (int i = 7; i >= 0; i--) {
System.out.print (" "+a[i]);
}
}
}
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 aaa;
public class E {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[]={1,25,1,3,1,22,89,63,25,18};
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a.length; j++) {
if (a[i]==a[j] && i!=j) {
a[j]=0;
}
}
}
for (int i : a) {
System.out.print(" "+i);
}
}
}
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 aaa;
public class E {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int a[]={-10,2,3,246,-100,0,5};
int max=a[0];
int min=a[0];
double sum=0;
for (int i = 0; i < a.length; i++) {
if (max<a[i]) {
max=a[i];
}
if (min>a[i]) {
min=a[i];
}
sum+=a[i];
}
sum=sum/7;
System.out.println("最大值"+max);
System.out.println("最小值"+min);
System.out.println("平均值"+sum);
}
}
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 aaa;
public class E {
/**
* @param args
*/
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 aaa;
import java.util.Arrays;
import java.util.Random;
public class E {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Random r = new Random();
int a[] = new int[10];
for (int i = 0; i < a.length; i++) {
a[i] = r.nextInt(101);
}
for (int i = 0; i < a.length; i++) {
System.out.print(a[i] + " ");
}
Arrays.sort(a);
System.out.println();
for (int i = 0; i < a.length; i++) {
System.out.print(a[i]+" ");
}
}
}