第八周上机课作业
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]?
package gkdhxd; public class test1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a=new int[5]; for (int i = 0; i < a.length; i++) { a[i]=10*(i+1); System.out.println(a[i]); } } }
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]?
package gkdhxd; public class test2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={1,3,6,4,8,3}; int []b=new int[6]; System.arraycopy(a, 0, b, 0, 6); for (int i = 0; i < b.length; i++) { System.out.println(b[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)
package gkdhxd; public class test3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={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-i; j++) { if (a[j]>a[j+1]) { int temp =a[j]; a[j]=a[j+1]; a[j+1]=temp; } } } 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 gkdhxd; public class test4 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double [][]a={{1,2,3,4},{6,7,8,9},{11,12,13,14},{16,17,18,19},{21,22,23,24}}; for (int i = 0; i < a.length; i++) { for (int j = 0; j < a.length-1; j++) { System.out.println(a[i][j]+" "); } } } }
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 gkdhxd; public class test5 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double score[]={18,25,7,36,13,2,89,63}; double max=score[0],min=score[0]; int maxidx=0,minidx=0; for (int i = 1; i < score.length; i++) { if (score[i]>max){ max=score[i]; maxidx=i; } if(score[i]<min){ min=score[i]; minidx=i; } } System.out.println("最大值是"+max+"它的下标是"+maxidx); System.out.println("最小值是"+min+"它的下标是"+minidx); } }
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 gkdhxd; public class test3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={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-i; j++) { if (a[j]<a[j+1]) { int temp =a[j]; a[j]=a[j+1]; a[j+1]=temp; } } } for (int i:a) { System.out.println(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 gkdhxd; public class test2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={1,3,6,4,8,3}; int []b=new int[6]; for (int i = 0; i < b.length; i++) { for (int j = 0; j < b.length; j++) { if (a[i]==a[j]&&i!=j) { a[j]=0; } } } for (int i:a) { System.out.println(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 gkd; import java.util.Random; import java.util.Scanner; public class test1 { public static void main(String[] args){ int []a={ -10,2,3,246,-100,0,5}; int max = a[0],min = a[0]; double sum = 0; for (int i = 1; i < a.length; i++) { if (a[i] > max) { max = a[i]; } if (a[i] < min) { min = a[i]; } } for (int i = 0; i < a.length; i++) { sum += a[i]; } System.out.println("最大值为" + max); System.out.println("最小值为" + min); System.out.println("平均值为" + 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 gkd; import java.util.Scanner; public class test1 { public static void main(String[] args){ int A[] = new int[20]; int a = 1,b = a,c = a + b; A[0] = a; A[1] = b; for(int i = 2; i < A.length; i++){ A[i] = c; a = b; b = c; c = a + b; } for(int i : A){ System.out.print(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 gkd; import java.util.Random; import java.util.Scanner; public class test1 { public static void main(String[] args){ int a[]=new int[10]; Random r= new Random(); for (int i = 0; i < a.length; i++) { int C=r.nextInt(100); a[i]=C; } for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } System.out.println(); for (int i = 0; i < a.length; i++) { for (int j = 0; j < a.length-1; j++) { int temp=a[j]; if(a[j]>a[j+1]){ a[j]=a[j+1]; a[j+1]=temp; } } } System.out.println("排序后顺序为:"); for (int j = 0; j < a.length; j++) { System.out.print(a[j]+" "); } } }