Set
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| class Solution {
public int[] intersection(int[] nums1, int[] nums2) {
Set<Integer> set1 = new HashSet<>();
for (int num : nums1) {
set1.add(num);
}
Set<Integer> set2 = new HashSet<>();
for (int num : nums2) {
set2.add(num);
}
set1.retainAll(set2);
int[] ans = new int[set1.size()];
int i = 0;
for (int num : set1) {
ans[i++] = num;
}
return ans;
}
}
|
Two Pointers
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| class Solution {
public int[] intersection(int[] nums1, int[] nums2) {
Arrays.sort(nums1);
Arrays.sort(nums2);
List<Integer> list = new ArrayList<>();
int index1 = 0, index2 = 0, targetIndex = 0;
while (index1 < nums1.length && index2 < nums2.length) {
int num1 = nums1[index1];
int num2 = nums2[index2];
if (num1 < num2) {
index1++;
} else if (num1 > num2) {
index2++;
} else {
if (targetIndex == 0 || list.get(targetIndex - 1) != num1) {
list.add(num1);
targetIndex++;
}
index1++;
index2++;
}
}
int[] array = new int[list.size()];
for (int i = 0; i < list.size(); i++) {
array[i] = list.get(i);
}
return array;
}
}
|
References
349. Intersection of Two Arrays