2956-FindCommonElementsBetweenTwoArrays.go

package main

// 2956. Find Common Elements Between Two Arrays
// You are given two integer arrays nums1 and nums2 of sizes n and m, respectively.
// Calculate the following values:
//     answer1 : the number of indices i such that nums1[i] exists in nums2.
//     answer2 : the number of indices i such that nums2[i] exists in nums1.

// Return [answer1,answer2].

// Example 1:
// Input: nums1 = [2,3,2], nums2 = [1,2]
// Output: [2,1]
// Explanation:
// <img scr="https://assets.leetcode.com/uploads/2024/05/26/3488_find_common_elements_between_two_arrays-t1.gif" />

// Example 2:
// Input: nums1 = [4,3,2,3,1], nums2 = [2,2,5,2,3,6]
// Output: [3,4]
// Explanation:
// The elements at indices 1, 2, and 3 in nums1 exist in nums2 as well. So answer1 is 3.
// The elements at indices 0, 1, 3, and 4 in nums2 exist in nums1. So answer2 is 4.

// Example 3:
// Input: nums1 = [3,4,2,3], nums2 = [1,5]
// Output: [0,0]
// Explanation:
// No numbers are common between nums1 and nums2, so answer is [0,0].

// Constraints:
//     n == nums1.length
//     m == nums2.length
//     1 <= n, m <= 100
//     1 <= nums1[i], nums2[i] <= 100

import "fmt"

func findIntersectionValues(nums1 []int, nums2 []int) []int {
    mp1, mp2 := make(map[int]bool), make(map[int]bool)
    res1, res2 := 0, 0
    for _, v := range nums1 { mp1[v] = true }
    for _, v := range nums2 { mp2[v] = true }
    for _, v := range nums1 {
        if _, ok := mp2[v]; ok {
            res1++
        }
    }
    for _, v := range nums2 {
        if _, ok := mp1[v]; ok {
            res2++
        }
    }
    return []int{ res1, res2 }
}

func findIntersectionValues1(nums1 []int, nums2 []int) []int {
    n, m := len(nums1), len(nums2)
    res := make([]int, 2)
    for i := 0; i < n; i++ {
        for j := 0; j < m; j++ {
            if nums1[i] == nums2[j] {
                res[0]++
                break
            }
        }
    }
    for j := 0; j < m; j++ {
        for i := 0; i < n; i++ {
            if nums2[j] == nums1[i] {
                res[1]++
                break
            }
        }
    }
    return res
}

func findIntersectionValues2(nums1 []int, nums2 []int) []int {
    res, arr1, arr2 := make([]int,2), make([]int, 101), make([]int, 101)
    for _, v := range nums1 { arr1[v]++ }
    for _, v := range nums2 { arr2[v]++ }
    for i := 1; i < 101; i++ {
        if arr1[i] != 0 && arr2[i] != 0 {
            res[0] += arr1[i]
            res[1] += arr2[i]
        }
    }
    return res
}

func main() {
    // Example 1:
    // Input: nums1 = [2,3,2], nums2 = [1,2]
    // Output: [2,1]
    // Explanation:
    // <img scr="https://assets.leetcode.com/uploads/2024/05/26/3488_find_common_elements_between_two_arrays-t1.gif" />
    fmt.Println(findIntersectionValues([]int{2,3,2}, []int{1,2})) // [2,1]
    // Example 2:
    // Input: nums1 = [4,3,2,3,1], nums2 = [2,2,5,2,3,6]
    // Output: [3,4]
    // Explanation:
    // The elements at indices 1, 2, and 3 in nums1 exist in nums2 as well. So answer1 is 3.
    // The elements at indices 0, 1, 3, and 4 in nums2 exist in nums1. So answer2 is 4.
    fmt.Println(findIntersectionValues([]int{4,3,2,3,1}, []int{2,2,5,2,3,6})) // [3,4]
    // Example 3:
    // Input: nums1 = [3,4,2,3], nums2 = [1,5]
    // Output: [0,0]
    // Explanation:
    // No numbers are common between nums1 and nums2, so answer is [0,0].
    fmt.Println(findIntersectionValues([]int{3,4,2,3}, []int{1,5})) // [0,0]

    fmt.Println(findIntersectionValues1([]int{2,3,2}, []int{1,2})) // [2,1]
    fmt.Println(findIntersectionValues1([]int{4,3,2,3,1}, []int{2,2,5,2,3,6})) // [3,4]
    fmt.Println(findIntersectionValues1([]int{3,4,2,3}, []int{1,5})) // [0,0]

    fmt.Println(findIntersectionValues2([]int{2,3,2}, []int{1,2})) // [2,1]
    fmt.Println(findIntersectionValues2([]int{4,3,2,3,1}, []int{2,2,5,2,3,6})) // [3,4]
    fmt.Println(findIntersectionValues2([]int{3,4,2,3}, []int{1,5})) // [0,0]
}