求子集、交集

// 子集
public static void subArrays2(int[] arr) {
int[] temp = new int[arr.length];
int index = 0;
for (int i = 0; i < arr.length; i++) {
for (int j = i + 1; j < arr.length; j++) {
if (arr[i] == arr[j]) {

temp[index++] = arr[i];
arr[i] = arr[arr.length - 1];
arr = Arrays.copyOf(arr, arr.length - 1);
Arrays.sort(arr);
i--;
break;
}
}
}
System.out.println("子集： " + Arrays.toString(arr));
temp = Arrays.copyOf(temp, index);
if (temp.length > 0) {
subArrays2(temp);
}
}

// 交集
public static int[] arrA(int[] a,int[] b){
int[] newarr=new int[a.length];
int index = 0;
for(int c=0;c<a.length;c++){
for(int d=0;d<b.length;d++){
if(a[c]==b[d]){
newarr[index++]=b[d];

}
}
}
newarr = Arrays.copyOf(newarr, index);
return newarr;
}