自顶 来大神 谢谢了

不要沉啊 大婶们 快来啊

大神呢

就是将生成的数放在第一位啦

扩容，复制

没有人给我说一下吗 大婶们

啥意思，n为5就把数组前5移到最后？

逆转两下

用数组复制就可以得到：
public class TestShuZu{
public static void main(String[] args) {
int[] a = { 23, 3, 33, 44, 56, 76872, 34, 45, 65, 6, 435, 789 };
int n =(int)(Math.random() * a.length);
int m=a.length-n;
System.out.println("随机N的位数："+n);
int[] b =new int[n];
System.arraycopy(a,0,b,0,n);
int[] c=new int[m];
System.arraycopy(a,n,c,0,m);
int[] d=new int[a.length];
System.arraycopy(c,0,d,0,m);
System.arraycopy(b,0,d,m,n);
System.out.println("d数组：");
for(int i=0; i<d.length;i++){
System.out.print(d[i]+" ");
}
}
}

public static void main(String args[]) {
int a[] = { 23, 3, 33, 44, 56, 76872, 34, 45, 65, 6, 435, 789 };
int n = new java.util.Random().nextInt(a.length);
System.out.println("The random >> " + n);
int newArr[] = move(a, n);
for(int i : newArr) {
System.out.print(i + " ");
}
}
private static int[] move(int a[], int n) {
int len = a.length;
if( n == 0 || n == len ) return a;
int newArr[] = new int[len];
for(int i = 0; i < len; i ++) {
newArr[i] = a[(n+i)%len];
}
return newArr;
}

用数组拷贝：
public class TestShuZu{
public static void main(String[] args) {
int[] a = { 23, 3, 33, 44, 56, 76872, 34, 45, 65, 6, 435, 789 };
int n =(int)(Math.random() * a.length);
int m=a.length-n;
System.out.println("随机N的位数："+n);
int[] b=new int[a.length];
System.arraycopy(a,n,b,0,m);
System.arraycopy(a,0,b,m,n);
System.out.println("b数组：");
for(int i=0; i<b.length;i++){
System.out.print(b[i]+" ");
}
}
}