211 字符串置换

class Solution {
public:
    /**
     * @param A: a string
     * @param B: a string
     * @return: a boolean
     */
    bool Permutation(string &A, string &B) {
        // write your code here
    int sizeA=A.size();
    int sizeB=B.size();
    if (sizeA!=sizeB)
    {
        return false;
    }
    map<char,int> m1;
    map<char,int> m2;
    for (int i=0;i<sizeA;i++)
    {
        if (m1.find(A[i])!=m1.end())//统计字符数量;
        {
            m1[A[i]]++;
        }
        else
        {
            m1[A[i]]=1;
        }
        if (m2.find(B[i])!=m2.end())//统计字符数量;
        {
            m2[B[i]]++;
        }
        else
        {
            m2[B[i]]=1;
        }
    }

    for (int i=0;i<sizeA;i++)
    {
        if (m1[A[i]]!=m2[A[i]])
        {
            return false;
        }
    }
    return true;
    }
};