package array;
public class ArrayDemo01 {
public static void main(String[] args) {
int[] nums = null;
nums = new int[5];
int[] nums2 = new int[3];
nums[0] = 1;
nums[1] = 2;
nums[2] = 3;
nums[3] = 4;
nums[4] = 5;
System.out.println(nums[2]);
System.out.println(nums2[2]);
int sum = 0;
for (int i = 0; i < nums.length; i++) {
sum += nums[i];
}
System.out.println(sum);
}
}
package array;
public class ArrayDemo02 {
public static void main(String[] args) {
int[] nums = {1,3,5,6,9};
double[] nums3 = {1,3,5,6,9};
Man[] mans = {new Man(),new Man()};
System.out.println(nums[3]);
System.out.println(mans[0]);
System.out.println(nums);
System.out.println(nums3);
int[] nums2 = new int[4];
int[] a = new int[5];
a[1] = 2;
a[3] = 3;
nums2[0] = 9;
nums2[1] = 3;
System.out.println(nums2[0]);
System.out.println(nums2[1]);
System.out.println(nums2[2]);
System.out.println(nums2[3]);
}
}
package array;
public class Man {
}
package array;
public class ArrayDemo03 {
public static void main(String[] args) {
int[] array = {1,2,3,4,5};
for (int i = 0; i < array.length; i++) {
System.out.print(array[i]+" ");
}
System.out.print("\n");
System.out.println("======================================");
int sum = 0;
for(int i=0;i<array.length;i++){
sum += array[i];
}
System.out.println("sum = "+sum);
System.out.println("===========================================");
int max = array[0];
for (int i=0;i<array.length;i++){
if(array[i]>max){
max = array[i];
}
}
System.out.println(max);
}
}
package array;
public class ArrayDemo04 {
public static void main(String[] args) {
int[] num = {1,3,5,7,9};
for(int a : num){
System.out.print(a+" ");
}
System.out.println();
System.out.println("========================");
double[] a = {1.1,1.5,1.3,1.7,1.9};
printArray(a);
System.out.println("========================");
int[] reverse = reverse(num);
printArray(reverse);
}
public static void printArray(double[] array){
for (int i = 0; i < array.length; i++) {
System.out.print(array[i]+" ");
}
System.out.println();
}
public static void printArray(int[] array){
for (int i = 0; i < array.length; i++) {
System.out.print(array[i]+" ");
}
System.out.println();
}
public static int[] reverse(int[] array){
int[] result = new int[array.length];
for(int i=0,j=result.length-1;i<array.length;i++,j--){
result[j] = array[i];
}
return result;
}
}
package array;
public class ArrayDemo05 {
public static void main(String[] args) {
int[][] nums = {{1,2},{2,3},{3,4},{4,5}};
int[][] nums1 = {{1,2},{2,3,4},{3,4,5,6},{4,5}};
printArray(nums[1]);
printArray(nums1[2]);
System.out.println(nums[2][0]);
System.out.println(nums.length);
System.out.println(nums[1].length);
System.out.println("========================");
for (int i = 0; i < nums.length; i++) {
for (int j = 0; j < nums[i].length; j++) {
System.out.print(nums[i][j]+" ");
}
}
System.out.println();
for (int i = 0; i < nums1.length; i++) {
for (int j = 0; j < nums1[i].length; j++) {
System.out.print(nums1[i][j]+" ");
}
}
}
public static void printArray(int[] array){
for (int i = 0; i < array.length; i++) {
System.out.print(array[i]+" ");
}
System.out.println();
}
}
package array;
import java.lang.reflect.Array;
import java.util.Arrays;
public class ArrayDemo06 {
public static void main(String[] args) {
int[] nums = {1,23,5,656,213123,72,123};
int[] nums1 = {1,23,5,656,213123,72,123};
System.out.println(nums);//[I@4554617c
System.out.println(Arrays.toString(nums));
printArray(nums);
System.out.println();
System.out.println("=======================================");
Arrays.sort(nums);
System.out.println(Arrays.toString(nums));
System.out.println("===========================================");
Arrays.fill(nums,2,5,3);
System.out.println(Arrays.toString(nums));
System.out.println("=========================================");
System.out.println(Arrays.equals(nums,nums1));
System.out.println("===========================================");
Arrays.sort(nums1);
System.out.println(Arrays.binarySearch(nums1,656));
System.out.println("===========================================");
int[] a = null;
a =new int[0];
System.out.println(Arrays.toString(a));
}
public static void printArray(int[] array){
System.out.print("[");
for (int i = 0; i < array.length; i++) {
if (i == array.length-1){
System.out.print(array[i]+"]");
}else {
System.out.print(array[i]+", ");
}
}
}
}
package array;
import java.util.Arrays;
public class Bubble {
public static void main(String[] args) {
int[] nums = {3,1,45,10062,1156,360,15};
Bubble bubble = new Bubble();
System.out.println(Arrays.toString(bubble.sort(nums)));
}
public int[] sort(int[] array){
int temp = 0;
for (int i = 0; i < array.length-1 ; i++) {
int flag = 0;
for (int j = 0; j < array.length-1-i; j++) {
if (array[j]<array[j+1]){
temp = array[j+1];
array[j+1] = array[j];
array[j] = temp;
flag = 1;
}
}
if (flag == 0){
break;
}
}
return array;
}
}
package array;
import java.util.Arrays;
public class SelectSort {
public static void main(String[] args) {
int[] nums = {3,1,45,10062,1156,360,15};
SelectSort sort = new SelectSort();
int[] a = sort.sort(nums);
System.out.println(Arrays.toString(a));
}
public int[] sort(int[] array){
int temp = 0;
for (int i = 0; i < array.length-1; i++) {
int minIndex = i;
for (int j = i+1; j < array.length; j++) {
if (array[minIndex]>array[j]){
minIndex = j;
}
}
if (i != minIndex){
temp = array[i];
array[i] = array[minIndex];
array[minIndex] = temp;
}
}
return array;
}
}
package array;
public class ArrayDemo07 {
public static void main(String[] args) {
int[][] array1 = new int[11][11];
array1[1][2] = 1;
array1[2][3] = 2;
array1[4][5] = 1;
System.out.println("原始数列：");
for (int[] nums1 : array1) {
for (int nums2 : nums1) {
System.out.print(nums2+"\t");
}
System.out.println();
}
System.out.println("=============================================");
int sum = 0;
for (int i = 0; i < array1.length; i++) {
for (int j = 0; j < array1[i].length; j++) {
if (array1[i][j] != 0){
sum ++;
}
}
}
int[][] array2 = new int[sum+1][3];
array2[0][0] = array1.length;
array2[0][1] = array1[0].length;
array2[0][2] = sum;
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];
}
}
}
System.out.println("转换为稀疏数组：");
for (int i = 0; i < array2.length; i++) {
for (int j = 0; j < array2[i].length; j++) {
System.out.print(array2[i][j]+"\t");
}
System.out.println();
}
System.out.println("===============================================");
int[][] array3 = new int[array2[0][0]][array2[0][1]];
for (int i = 1; i < array2.length; i++) {
array3[array2[i][0]][array2[i][1]] = array2[i][2];
}
System.out.println("还原：");
for (int[] ints : array3) {
for (int anInt : ints){
System.out.print(anInt+"\t");
}
System.out.println();
}
}
}
时间复杂度怎么算的 八大排序算法
标签：nums,int,System,println,array,out From： https://www.cnblogs.com/799rijiyuelei/p/16860694.html