Some of the most difficult exercises in Java arrays

1. The n random number of [0-n] is stored in an array, requiring that the data not be duplicated.

Import Java.util.Random;
Import Java.util.Scanner;
public class Homework04_2 {
public static void Main (string[] args) {
Scanner sc = new Scanner (system.in);
SYSTEM.OUT.PRINTLN ("Please input n, will generate n random number into array array[n]");
int n = sc.nextint ();
int a[] = new Int[n];
Suiji (A,n);
}
public static void Suiji (int a[],int N)
{
Random r= new Random ();
for (int i=0;i<n;i++)
{
int number = R.nextint (n);
Boolean s;
do{
S= false;
for (int j=0;j<i;j++)
{
if (number = = A[j])
{
Number = R.nextint (n);
S=true;
Break
}
}
}while (s);
A[i]=number;
}
for (int j=0;j<n;j++)
{
System.out.println (A[j]);
}
}

}

1.2

public class Homework04_2 {
public static void Main (string[] args) {
Scanner sc = new Scanner (system.in);
SYSTEM.OUT.PRINTLN ("Please input n, will generate n random number into array array[n]");
int n = sc.nextint ();
int a[] = new Int[n];
Suiji (A,n);
}
public static void Suiji (int a[],int N)
{
Random r= new Random ();
int c=0;
Outer:while (C<n)
{
int s=r.nextint (n);
for (int i=0;i<c;i++)
{
if (a[i]==s)
Continue Outer;
}
A[c]=s;
C + +;
}
for (int i=0;i<n;i++)
{
System.out.println (A[i]);
}
}


}

2. Design a method to disrupt the order of the data in the array

Import Java.util.Random;


public class Homework05 {
public static void Main (string[] args) {
int n = ten;
int A[]=disorder (n);
for (int i=0;i<n;i++)
{
System.out.println (a[i]);
}

}
public static int[] disorder (int n)
{
Random r = new Random ();
int a[] = new int [n];
for (int i=0;i<n;i++)
{
A[i] = i;
}
for (int i=0;i<n/2;i++)
{
int number = R.nextint (n);
int temp = A[i];
A[i] = A[number];
A[number] = temp;
}
return A;
}
}

3. Removes duplicates from the array {1,3,1,4,2,3,6,1,5}, stores a new array, and sorts from large to small.


public class Homework08 {
public static void Main (string[] args) {
int arr[] = {1, 3, 1, 4, 2, 3, 6, 1, 5};


int number = 0;
int count = 0;


for (int i = 0; i < arr.length-1. i++) {
for (int j = 1; j < Arr.length-i; J +) {
Int temp = 0 ;
if (Arr[j] > Arr[j-1]) {
temp = arr[j];
ARR[J] = arr[j-1];
Arr[j-1] = temp;
}
}



for (int i = 0; i < arr.length; i++) {
number = Arr[i];
Boolean s = true;
for (int j = 0; J < i; J + +) {
if (number = = Arr[j]) {
count++;
S=false;
}
}
if (!s) {
Arr[i] =-1;
} else {
Arr[i] = number;
}
}
int b[] = new Int[arr.length-count];
int j = 0;
for (int i = 0; i < arr.length i++) {
if (Arr[i]!=-1) {
B[j] = arr[i];
j + +;
}
}
for (int i = 0; i < b.length i++) {
System.out.println (b[i]);
}


}
}

4. Given an integral array of n elements such as {1,1,1,2,4,3,3}, the output of some elements if they appear to be odd several times: for example, 1,2,4


public class Homework09 {
public static void Main (string[] args) {
int a[] = {1, 1, 1, 2, 4, 3, 3};
int c[] = new Int[a.length];
int number = 0;
int count = 0;
for (int q = 0; q < a.length; q++) {
C[Q] = A[q];
System.out.println (C[q]);
}


for (int i = 0; i < a.length; i++) {
Boolean s = true;
Number = A[i];


for (int j = 0; J < i; J + +) {
if (number = = A[j])
s = false;


}
if (!s) {
count++;
A[i] =-1;
} else {
A[i] = number;
}
}
int b[] = new Int[a.length-count];
int count1 = 0;
for (int k = 0; k < a.length; k++) {
if (A[k]!=-1) {
B[COUNT1] = a[k];
count1++;
}
}
for (int z=0;z<b.length;z++)
// {
System.out.println (B[z]);
// }


for (int m = 0; m < b.length; m++) {
Number = B[m];
int count2 = 0;
for (int n = 0; n < c.length; n++) {
if (number = = C[n])
count2++;
}
if (count2% 2!= 0) {
System.out.println (B[m]);
}
}


}
}