Intersection of Two Arrays II

class Solution {
public:
    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
        if (nums1.size() > nums2.size()) return intersect(nums2, nums1);
        unordered_map<int,int> cnt;
        for (int v : nums1) ++cnt[v];
        vector<int> ans;
        for (int v : nums2) {
            auto it = cnt.find(v);
            if (it != cnt.end() && it->second > 0) { ans.push_back(v); --it->second; }
        }
        return ans;
    }
};

func intersect(nums1 []int, nums2 []int) []int {
    if len(nums1) > len(nums2) {
        return intersect(nums2, nums1)
    }
    cnt := make(map[int]int)
    for _, v := range nums1 {
        cnt[v]++
    }
    ans := []int{}
    for _, v := range nums2 {
        if c, ok := cnt[v]; ok && c > 0 {
            ans = append(ans, v)
            cnt[v]--
        }
    }
    return ans
}

from typing import List
from collections import Counter

class Solution:
    def intersect(self, nums1: List[int], nums2: List[int]) -> List[int]:
        if len(nums1) > len(nums2):
            return self.intersect(nums2, nums1)
        cnt = Counter(nums1)
        ans: List[int] = []
        for v in nums2:
            if cnt[v] > 0:
                ans.append(v)
                cnt[v] -= 1
        return ans

function intersect(nums1, nums2) {
    if (nums1.length > nums2.length) return intersect(nums2, nums1);
    const cnt = new Map();
    for (const v of nums1) cnt.set(v, (cnt.get(v) ?? 0) + 1);
    const ans = [];
    for (const v of nums2) {
        const c = cnt.get(v);
        if (c !== undefined && c > 0) {
            ans.push(v);
            cnt.set(v, c - 1);
        }
    }
    return ans;
}

class Solution {
    public int[] intersect(int[] nums1, int[] nums2) {
        if (nums1.length > nums2.length) return intersect(nums2, nums1);
        Map<Integer, Integer> cnt = new HashMap<>();
        for (int v : nums1) cnt.merge(v, 1, Integer::sum);
        List<Integer> ans = new ArrayList<>();
        for (int v : nums2) {
            Integer c = cnt.get(v);
            if (c != null && c > 0) {
                ans.add(v);
                cnt.put(v, c - 1);
            }
        }
        int[] out = new int[ans.size()];
        for (int i = 0; i < ans.size(); i++) out[i] = ans.get(i);
        return out;
    }
}

function intersect(nums1: number[], nums2: number[]): number[] {
    if (nums1.length > nums2.length) return intersect(nums2, nums1);
    const cnt: Map<number, number> = new Map();
    for (const v of nums1) cnt.set(v, (cnt.get(v) ?? 0) + 1);
    const ans: number[] = [];
    for (const v of nums2) {
        const c = cnt.get(v);
        if (c !== undefined && c > 0) {
            ans.push(v);
            cnt.set(v, c - 1);
        }
    }
    return ans;
}