打印所有可能只能移动1个索引的可能的回文

Question

我正在尝试打印一个程序，打印所有可能产生的回文，重新排列涉及一个字符以最大1个索引改变其位置，这意味着只允许相邻字符的交换。

我尝试了很多代码，但最好的代码是下一代。

只有我可以重新安排所有可能的回文，但所有的改变（不仅仅是一个）

CODE

#include <bits/stdc++.h>

using namespace std;
#define M 26

bool caNformPalindrome(string str, int* count_array)
{
    //Initialize array with zeroes
    for (int i = 0; i < 26; ++i)
    {
        count_array[i] = 0;
    }
    int length = str.length();

    /* Updating frequency according to given string */
    for (int i = 0; i < length; i++)
    {
        count_array[str[i] - 'a']++;
    }
    int odd_count = 0;
    //Find odd_count
    for (int i = 0; i < M; i++)
    {
        if (count_array[i] % 2 == 1)
        {
            odd_count++;
        }
    }
    //if length is odd_count then only one letter's frequency must be odd_count
    if ((length % 2 == 1 && odd_count == 1 ) || (length %2 == 0 && odd_count == 0))
    {
        return true;
    }
    else//if length is even no letter should have odd_count frequency
    {
        return false;
    }
}
//Function to reverse the string
string reverse(string str)
{
    string rev = str;
    reverse(rev.begin(), rev.end());
    return rev;
}

//Function to print 
void printPalIndromes(string str)
{
    int count_array[M];
    // checking whether letter can make palindrome or not
    if (!caNformPalindrome(str, count_array))
    {
        return;
    }
    int length = str.length();

    // half will contain half part of all palindromes,
    // that is why pushing half count_array of each letter
    string half = "";
    char mid;//store odd count charcter
    for (int i = 0; i < M; i++)
    {
        if(count_array[i] % 2 == 1)
        {
            mid = i + 'a';
        }
        half += string(count_array[i] / 2, i + 'a');
    }
    string palindrome_string;
    do
    {
        palindrome_string = half;
        if (length % 2 == 1)
        {
            palindrome_string += mid;
        }
        palindrome_string += reverse(half);
        cout<<palindrome_string<<endl;
    }
    while (next_permutation(half.begin(), half.end()));
}

//Main function
int main()
{
    string str = "aabbc";
    cout<<"Possible Permutations for Input_string only with 1 change"<<str<<" are: "<<endl;
    printPalIndromes(str);
    return 0;
}