JAVA请从控制台输入一个整数N,随机产生该N*N范围内的数字(含1和N),不可重复？

import java.util.Scanner

import java.util.Random

public class Main {

public static void main(String[] args) {

Scanner input = new Scanner(System.in)

Random random = new Random()

System.out.print("请输入一个整数N：")

int n = input.nextInt()

if (n <1) {

System.out.println("请输入大于等于1的整数！")

return

}

if (n == 1) {

System.out.println("1")

return

}

int[] arr = new int[n * n]

for (int i = 0i <arr.lengthi++) {

arr[i] = i + 1

}

for (int i = 0i <arr.lengthi++) {

int j = random.nextInt(n * n - i) + i

int temp = arr[i]

arr[i] = arr[j]

arr[j] = temp

}

int index = 0

for (int i = 0i <ni++) {

for (int j = 0j <nj++) {

System.out.print(arr[index++] + " ")

}

System.out.println()

}

}

}

import java.util.Scanner

public class Test {

public static void main(String[] args) {

System.out.println("请输入一个数字n")

int type = 1

int sum = 0

Scanner sc = new Scanner(System.in)

int n = sc.nextInt()

for(int i=1i<=ni++){

sum=sum+i*type

System.out.print(i*type)

if(i!=n&&type==-1){

System.out.print("+")

}

type*=-1

}

System.out.print("="+sum)

}

}

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