Algorithm
Problem Name: 349. Intersection of Two Arrays
Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the result in any order.
Example 1:
Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2]
Example 2:
Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4] Output: [9,4] Explanation: [4,9] is also accepted.
Constraints:
1 <= nums1.length, nums2.length <= 10000 <= nums1[i], nums2[i] <= 1000
Code Examples
#1 Code Example with C Programming
Code -
C Programming
class Solution {
public int[] intersection(int[] nums1, int[] nums2) {
boolean[][] found = new boolean[1001][2];
for (int num : nums1) {
found[num][0] = true;
}
int count = 0;
for (int num : nums2) {
if (!found[num][1]) {
if (found[num][0]) {
count++;
}
}
found[num][1] = true;
}
int[] result = new int[count];
int idx = 0;
for (int i = 1; i < = 1000; i++) {
if (found[i][0] && found[i][1]) {
result[idx++] = i;
}
}
return result;
}
}
Input
nums1 = [1,2,2,1], nums2 = [2,2]
Output
[2]
#2 Code Example with Javascript Programming
Code -
Javascript Programming
const intersection = function(nums1, nums2) {
const obj = {};
nums1.forEach(i => (obj[i] = true));
return nums2.filter(j => {
if (obj[j]) {
delete obj[j];
return true;
}
return false;
});
};
Input
nums1 = [1,2,2,1], nums2 = [2,2]
Output
[2]
#3 Code Example with Python Programming
Code -
Python Programming
class Solution:
def intersection(self, nums1, nums2):
"""
:type nums1: List[int]
:type nums2: List[int]
:rtype: List[int]
"""
return list(set(nums1)&set(nums2))
Input
nums1 = [4,9,5], nums2 = [9,4,9,8,4]
Output
[9,4]
#4 Code Example with C# Programming
Code -
C# Programming
using System.Collections.Generic;
namespace LeetCode
{
public class _0349_IntersectionOfTwoArrays
{
public int[] Intersection(int[] nums1, int[] nums2)
{
var set1 = new HashSet < int>(nums1);
var set2 = new HashSet<int>(nums2);
var result = new List < int>();
foreach (var num in set1)
if (set2.Contains(num)) result.Add(num);
return result.ToArray();
}
}
}
Input
nums1 = [4,9,5], nums2 = [9,4,9,8,4]
Output
[9,4]