18>palindromeRearranging

Given a string, find out if its characters can be rearranged to form a palindrome. Example For inputString = "aabb", the output should be palindromeRearranging(inputString) = true. We can rearrange "aabb" to make "abba", which is a palindrome.

code>>

bool palindromeRearranging(std::string inputString) {

int alphabat[27] = { 0, };

for (int i = 0; i < inputString.size(); i++)

{

alphabat[inputString[i] - 'a']++;

}

int count = 0;

for (int i = 0; i < 27; i++)

{

count += alphabat[i] % 2;

}

return inputString.size() % 2 == count;

}

비트 연산으로 푼 풀이들

int A[256];

bool palindromeRearranging(std::string inputString) {

    for(char i:inputString)

        ++A[i];

    int c = 0;

    for(int i = 0; i < 256; ++i)

        c += A[i]&1;

    return c<2;

}

bool palindromeRearranging(std::string inputString) {

    std::vector<int> cnt(26);

    for (auto it : inputString)

        cnt[it - 'a']++;

    

    int oddCount = 0;

    for (int i = 0; i < 26; ++i)

        if (cnt[i] & 1)

            oddCount++;

    

    return oddCount < 2;

}