760. Find Anagram Mappings

Given two lists Aand 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 ith 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 0th element of A appears at B[1], and P[1] = 4 because the 1st element of A appears at B[4], and so on.

 

Note:

1. A, B have equal lengths in range [1, 100].
2. A[i], B[i] are integers in range [0, 10^5].

找出A中的每个元素对应B中的哪个位置

C++（9ms）：

class Solution {
public:
    vector<int> anagramMappings(vector<int>& A, vector<int>& B) {
        unordered_map<int,int> m ;
        vector<int> res ;
        for(int i = 0 ; i < B.size() ; i++){
            m[B[i]] = i ;
        }
        for(int i : A){
            res.push_back(m[i]) ;
        }
        return res; 
    }
};