企业官网建设流程全解析

Arrays工具包

package com.fatbread.array; import java.util.Arrays; public class ArrayDemo06 { public static void main(String[] args) { int[] a = {2132,4233425,1312312,34634653}; //打印数组元素 System.out.println(Arrays.toString(a)); //[2132, 4233425, 1312312, 34634653] //给数组重新排序（升序） Arrays.sort(a); System.out.println(Arrays.toString(a)); //[2132, 1312312, 4233425, 34634653] //填充数组 Arrays.fill(a,2,4,0); //2、3位填充0 System.out.println(Arrays.toString(a)); //[2132, 1312312, 0, 0] } }

冒泡排序

package com.fatbread.array; import java.util.Arrays; public class ArrayDemo07 { public static void main(String[] args) { int[] a = {1323123,12431412,3254252,465464564}; System.out.println(Arrays.toString(sort(a))); //[1323123, 3254252, 12431412, 465464564] } //冒泡排序 public static int[] sort(int[] a){ for (int i = 0; i < a.length-1; i++) { boolean flag = false; for (int j = 0; j < a.length - 1 - i; j++) { if (a[j]>a[j+1]){ int bigger = a[j]; a[j] = a[j+1]; a[j+1] = bigger; flag = true; } } if (flag == false){ break; } } return a; } }

稀疏数组

稀疏数组是将原数组里不为0的有效元素提取出来组成内存更小的新数组。

package com.fatbread.array; import java.util.Arrays; public class ArrayDemo08 { public static void main(String[] args) { //创建一个二维数组，11*11，0为空，1为白子，2为黑子 int[][] a = new int[11][11]; a[2][3] = 1; a[3][2] = 2; //遍历数组 for (int[] ints : a) { //遍历每一行 for (int anInt : ints) { //遍历一行中每一个数 System.out.print(anInt+"\t"); } System.out.println(); } System.out.println("======================"); //转换为稀疏数组 //先获取有效值的个数 int count = 0; for (int[] ints : a) { //遍历每一行 for (int anInt : ints) { //遍历一行中每一个数 if (anInt!=0){ count++; } } } System.out.println(count); System.out.println("======================"); //创建一个稀疏数组的数组 int[][] b = new int[count+1][3]; b[0][0] = 11; b[0][1] = 11; b[0][2] = count; //提取原数组中的有效数据并赋予给稀疏数组 int sum = 0; for (int i = 0; i < 11; i++) { for (int j = 0; j < 11; j++) { if (a[i][j]!=0){ sum++; b[sum][0] = i+1; b[sum][1] = j+1; b[sum][2] = a[i][j]; } } } //遍历稀疏数组 for (int[] ints : b) { //遍历每一行 for (int anInt : ints) { //遍历一行中每一个数 System.out.print(anInt+"\t"); } System.out.println(); } System.out.println("======================"); //将稀疏数组转换回普通数组 //识别稀疏数组里的值 int[][] c = new int[11][11]; int x = 0; int y = 0; int z = 0; for (int i = 1; i < count + 1; i++) { x = b[i][0]; y = b[i][1]; z = b[i][2]; c[x-1][y-1] = z; } //遍历稀疏数组 for (int[] ints : c) { //遍历每一行 for (int anInt : ints) { //遍历一行中每一个数 System.out.print(anInt+"\t"); } System.out.println(); } } }