[LeetCode] Find Anagram Mappings 尋找異構對映
阿新 • • 發佈:2018-12-27
Given two lists A
and B
, and B
is an anagram of A
. B
is an anagram of A
means B
is made by randomizing the order of the elements in A
.
We want to find an index mapping P
, from A
to B
. A mapping P[i] = j
means the i
th element in A
appears in B
at index j
.
These lists A
and B
may contain duplicates. If there are multiple answers, output any of them.
For example, given
A = [12, 28, 46, 32, 50] B = [50, 12, 32, 46, 28]
We should return
[1, 4, 3, 2, 0]
as P[0] = 1
because the 0
th element of A
appears at B[1]
, and P[1] = 4
because the 1
st element of A
appears at B[4]
, and so on.
Note:
A, B
have equal lengths in range[1, 100]
.A[i], B[i]
[0, 10^5]
.
這道題給了我們兩個陣列A和B,說是A和B中的數字都相同,但是順序不同,有點類似錯位詞的感覺。讓我們找出陣列A中的每個數字在陣列B中的位置。這道題沒有太大的難度,用個HashMap建立陣列B中的每個數字和其位置之間的對映,然後遍歷陣列A,在HashMap中查詢每個數字的位置即可,參見程式碼如下:
class Solution { public: vector<int> anagramMappings(vector<int>& A, vector<int>& B) { vector<int> res; unordered_map<int, int> m; for (int i = 0; i < B.size(); ++i) m[B[i]] = i; for (int num : A) res.push_back(m[num]); return res; } };
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