2363. Merge Similar Items
Description
You are given two 2D integer arrays, items1
and items2
, representing two sets of items. Each array items
has the following properties:
items[i] = [valuei, weighti]
wherevaluei
represents the value andweighti
represents the weight of theith
item.- 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
initems1
is unique. - Each
valuei
initems2
is unique.
Solutions
Solution 1: Hash Table or Array
We can use a hash table or array cnt
to count the total weight of each item in items1
and items2
. Then, we traverse the values in ascending order, adding each value and its corresponding total weight to the result array.
The time complexity is $O(n + m)$ and the space complexity is $O(n + m)$, where $n$ and $m$ are the lengths of items1
and items2
respectively.
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