Find Anagram Mappings

Problem

You are given two integer arrays nums1 and nums2 where nums2 is an anagram of nums1. Both arrays may contain duplicates.

Return an index mapping array mapping from nums1 to nums2 where mapping[i] = j means the ith element in nums1 appears in nums2 at index j. If there are multiple answers, return any of them.

An array a is an anagram of an array b means b is made by randomizing the order of the elements in a.

Constraints

• 1 <= nums1.length <= 100
• nums2.length == nums1.length
• 0 <= nums1[i], nums2[i] <= 105
• nums2 is an anagram of nums1.

Solution

The problem Find Anagram Mappings can be solved by creating a queue of indexes for each elements.

Implementation

static const int fast_io = []()
{
    std::ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    return 0;
}();

class Solution
{
  public:
    vector<int> anagramMappings(vector<int> &nums1, vector<int> &nums2)
    {
        unordered_map<int, queue<int>> hashmap;
        for (int i = 0; i < nums2.size(); i++)
            hashmap[nums2[i]].push(i);

        vector<int> ret;
        for (int &num : nums1)
        {
            ret.push_back(hashmap[num].front());
            hashmap[num].pop();
        }

        return ret;
    }
};