Array

package Demo05;

import java.util.Arrays;

public class ArrayDemo05 {
public static void main(String[] args) {
int[] a = {1, 2, 3, 44, 55, 777, 666};
//打印数组元素 Arrays.toString
System.out.println(Arrays.toString(a));
printAra(a);
Arrays.sort(a);//数组进行排序
System.out.println(Arrays.toString(a));
Arrays.fill(a,0);//数组填充
System.out.println(Arrays.toString(a));
}
public static void printAra(int[] a){
for (int i = 0; i < a.length; i++) {
if (i0){
System.out.print("[");
}
if (i a.length-1){
System.out.print(a[i]+"]");
}else {
System.out.print(a[i] + "，");
}
}
}
}

package Demo05;

public class ArrayDemo07 {
public static void main(String[] args) {
//1. 创建一个2维数组11*11 0：没有棋子， 1：黑棋 2：白棋

int[][] array1 = new int[11][11];
array1[1][2] = 1;
array1[2][3] = 2;
//输出原始的数组
System.out.println("输出原始的数组");

for (int[] ints : array1) {
for (int anInt : ints) {
System.out.print(anInt+"\t");
}
System.out.println();
}
//转换为稀疏数组保存
//获取有效值的个数
int sum = 0;
for (int i= 0; i <11 ; i++) {
for (int j = 0; j < 11; j++) {
if (array1[i][j] != 0) {
sum++;
}
}
}
System.out.println("有效值的个数"+sum);
//2.创建一个稀疏数组的数组
int[][] array2 = new int[sum+1][3];
array2[0][0] = 11;
array2[0][1] = 11;
array2[0][2] = sum;

//遍历2维数组，将非0的值，存放稀疏数组中
int count=0;
for (int i = 0; i <array1.length ; i++) {
for (int j = 0; j < array1[i].length; j++) {
if (array1[i][j] != 0) {
count++;
array2[count][0] = i;
array2[count][1] = j;
array2[count][2] = array1[i][j];
}
}
}
//输出稀疏数组
System.out.println("稀疏数组");

for (int i = 0; i < array2.length; i++) {
System.out.println(array2[i][0]+"\t"
+array2[i][1]+"\t"
+array2[i][2]);
}
System.out.println("=============");
System.out.println("还原");
//1.读取稀疏数组
int[][] array3 = new int[array2[0][0]][array2[0][1]];

//2.给其中的元素还原它的值
for (int i = 1; i < array2.length; i++) {
array3[array2[i][0]][array2[i][1]] = array2[i][2];
}
//输出原始的数组
System.out.println("输出原始的数组");

for (int[] ints : array3) {
for (int anInt : ints) {
System.out.print(anInt+"\t");
}
System.out.println();
}
}
}