2363-MergeSimilarItems.go

package main

// 2363. Merge Similar Items
// You are given two 2D integer arrays, items1 and items2, representing two sets of items. 
// Each array items has the following properties:
//     1. items[i] = [valuei, weighti] where valuei represents the value and weighti represents the weight of the ith item.
//     2. The value of each item in items is unique.

// Return a 2D integer array ret where ret[i] = [valuei, weighti], with weighti being the sum of weights of all items with value valuei.

// Note: ret should be returned in ascending order by value.

// Example 1:
// Input: items1 = [[1,1],[4,5],[3,8]], items2 = [[3,1],[1,5]]
// Output: [[1,6],[3,9],[4,5]]
// Explanation: 
// The item with value = 1 occurs in items1 with weight = 1 and in items2 with weight = 5, total weight = 1 + 5 = 6.
// The item with value = 3 occurs in items1 with weight = 8 and in items2 with weight = 1, total weight = 8 + 1 = 9.
// The item with value = 4 occurs in items1 with weight = 5, total weight = 5.  
// Therefore, we return [[1,6],[3,9],[4,5]].

// Example 2:
// Input: items1 = [[1,1],[3,2],[2,3]], items2 = [[2,1],[3,2],[1,3]]
// Output: [[1,4],[2,4],[3,4]]
// Explanation: 
// The item with value = 1 occurs in items1 with weight = 1 and in items2 with weight = 3, total weight = 1 + 3 = 4.
// The item with value = 2 occurs in items1 with weight = 3 and in items2 with weight = 1, total weight = 3 + 1 = 4.
// The item with value = 3 occurs in items1 with weight = 2 and in items2 with weight = 2, total weight = 2 + 2 = 4.
// Therefore, we return [[1,4],[2,4],[3,4]].

// Example 3:
// Input: items1 = [[1,3],[2,2]], items2 = [[7,1],[2,2],[1,4]]
// Output: [[1,7],[2,4],[7,1]]
// Explanation:
// The item with value = 1 occurs in items1 with weight = 3 and in items2 with weight = 4, total weight = 3 + 4 = 7. 
// The item with value = 2 occurs in items1 with weight = 2 and in items2 with weight = 2, total weight = 2 + 2 = 4. 
// The item with value = 7 occurs in items2 with weight = 1, total weight = 1.
// Therefore, we return [[1,7],[2,4],[7,1]].

// Constraints:
//     1 <= items1.length, items2.length <= 1000
//     items1[i].length == items2[i].length == 2
//     1 <= valuei, weighti <= 1000
//     Each valuei in items1 is unique.
//     Each valuei in items2 is unique.

import "fmt"
import "sort"

func mergeSimilarItems(items1 [][]int, items2 [][]int) [][]int {
    mp := make(map[int]int)
    for _, v := range items1 {
        mp[v[0]] += v[1]
    }
    for _, v := range items2 {
        mp[v[0]] += v[1]
    }
    res := make([][]int, 0, len(mp))
    for k, v := range mp {
        res = append(res, []int{ k, v })
    }
    sort.Slice(res, func(i, j int) bool { 
        return res[i][0] < res[j][0] 
    })
    return res
}

func mergeSimilarItems1(items1 [][]int, items2 [][]int) [][]int {
    mp := make([]int, 1001)
    for _, v := range items1 {
        mp[v[0]] += v[1]
    }
    for _, v := range items2 {
        mp[v[0]] += v[1]
    }
    res := [][]int{}
    for k, v := range mp {
        if v == 0 { continue }
        res = append(res, []int{ k, v })
    }
    return res
}

func main() {
    // Example 1:
    // Input: items1 = [[1,1],[4,5],[3,8]], items2 = [[3,1],[1,5]]
    // Output: [[1,6],[3,9],[4,5]]
    // Explanation: 
    // The item with value = 1 occurs in items1 with weight = 1 and in items2 with weight = 5, total weight = 1 + 5 = 6.
    // The item with value = 3 occurs in items1 with weight = 8 and in items2 with weight = 1, total weight = 8 + 1 = 9.
    // The item with value = 4 occurs in items1 with weight = 5, total weight = 5.  
    // Therefore, we return [[1,6],[3,9],[4,5]].
    fmt.Println(mergeSimilarItems([][]int{{1,1},{4,5},{3,8}}, [][]int{{3,1},{1,5}})) // [[1,6],[3,9],[4,5]]
    // Example 2:
    // Input: items1 = [[1,1],[3,2],[2,3]], items2 = [[2,1],[3,2],[1,3]]
    // Output: [[1,4],[2,4],[3,4]]
    // Explanation: 
    // The item with value = 1 occurs in items1 with weight = 1 and in items2 with weight = 3, total weight = 1 + 3 = 4.
    // The item with value = 2 occurs in items1 with weight = 3 and in items2 with weight = 1, total weight = 3 + 1 = 4.
    // The item with value = 3 occurs in items1 with weight = 2 and in items2 with weight = 2, total weight = 2 + 2 = 4.
    // Therefore, we return [[1,4],[2,4],[3,4]].
    fmt.Println(mergeSimilarItems([][]int{{1,1},{3,2},{2,3}}, [][]int{{2,1},{3,2},{1,3}})) // [[1,4],[2,4],[3,4]]
    // Example 3:
    // Input: items1 = [[1,3],[2,2]], items2 = [[7,1],[2,2],[1,4]]
    // Output: [[1,7],[2,4],[7,1]]
    // Explanation:
    // The item with value = 1 occurs in items1 with weight = 3 and in items2 with weight = 4, total weight = 3 + 4 = 7. 
    // The item with value = 2 occurs in items1 with weight = 2 and in items2 with weight = 2, total weight = 2 + 2 = 4. 
    // The item with value = 7 occurs in items2 with weight = 1, total weight = 1.
    // Therefore, we return [[1,7],[2,4],[7,1]].
    fmt.Println(mergeSimilarItems([][]int{{1,3},{2,2}}, [][]int{{7,1},{2,2},{1,4}})) // [[1,7],[2,4],[7,1]]

    fmt.Println(mergeSimilarItems1([][]int{{1,1},{4,5},{3,8}}, [][]int{{3,1},{1,5}})) // [[1,6],[3,9],[4,5]]
    fmt.Println(mergeSimilarItems1([][]int{{1,1},{3,2},{2,3}}, [][]int{{2,1},{3,2},{1,3}})) // [[1,4],[2,4],[3,4]]
    fmt.Println(mergeSimilarItems1([][]int{{1,3},{2,2}}, [][]int{{7,1},{2,2},{1,4}})) // [[1,7],[2,4],[7,1]]
}