package myapps;
import java.util.Scanner;
public class Practice {
public static void main(String[] args) {
Homework homework = new Homework();
System.out.println("打印金字塔,请输入金字塔层数:");
Scanner input = new Scanner(System.in);
homework.printTower(input.nextInt());
System.out.println("----------------------------------");
System.out.println("打印乘法表,请输入数字:");
homework.printTable(input.nextInt());
System.out.println("----------------------------------");
int[][] arr = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
System.out.println("数组转置前:");
printArray(arr);
homework.transpose(arr);//数组转置
System.out.println("数组转置后:");
printArray(arr);
input.close();
}
//打印二维数组
private static void printArray(int[][] arr) {
for (int i = 0; i < arr.length; i++) {
System.out.print("{");
for (int j = 0; j < arr[i].length; j++) {
System.out.print(arr[i][j]);
if (j != arr[i].length - 1) {
System.out.print(",");
}
}
System.out.print("}");
if (i != arr.length - 1) {
System.out.print(",");
}
}
System.out.println();
}
}
class Homework {
/*
* 打印金字塔
*/
public void printTower(int layer) {
for (int i = 0; i < layer; i++) {
for (int j = 0; j < (2 * layer + 1); j++) {
if ((j < layer - i - 1) || (j >= layer + i)) {
System.out.print(" ");
} else {
System.out.print("*");
}
}
System.out.println();
}
}
/*
* 打印九九乘法表
*/
public void printTable(int num) {
for (int i = 1; i <= num; i++) {
for (int j = 1; j <= i; j++) {
System.out.print(j + "×" + i + "=" + (i * j) + "\t");
}
System.out.println();
}
}
/*
* 数组转置
*/
public void transpose(int[][] arr) {
for (int i = 0; i < arr.length - 1; i++) {
for (int j = 0; j < arr[i].length; j++) {
if (j > i) {
int temp = arr[i][j];
arr[i][j] = arr[j][i];
arr[j][i] = temp;
}
}
}
}
}
运行结果: