理清题意是在要求什么,永远是第一要务,这个和那个list找交集的题,并不相同,同题意到输出,两回事,不要混淆了
public class Solution {
public int[] intersection(int[] nums1, int[] nums2) {
//int [] result = null;
int [] result = new int[0];
if (nums1 == null || nums1.length == 0 || nums2 == null || nums2.length == 0) {
return result;
}
Set<Integer> set1 = new HashSet<>();
for (int i: nums1) {
set1.add(i);
}
Set<Integer> set2 = new HashSet<>();
for (int i: nums2) {
if (set1.contains(i)) {
set2.add(i);
}
}
result = new int[set2.size()];
Iterator<Integer> it = set2.iterator();
int i = 0;
while(it.hasNext()){
result[i++] = it.next();
}
return result;
}
}