Зашифровать текст по спирали

#include <windows.h>
#include <cmath>
#include <iostream>
using namespace std;
int main(){
    //setlocale(LC_ALL, "Russian");
    SetConsoleCP(1251);
    SetConsoleOutputCP(1251);
    string s;
    cout << "Текст: ";
    getline(cin, s);
    while (sqrt(s.length()) != (int)sqrt(s.length()) || (int)sqrt(s.length()) % 2 == 0)
        s += ' ';
    int n = (int)sqrt(s.length());
    char a[n][n];
    for (int i = 0; i < s.length(); ++i){
        if (i && i % n == 0)
            cout << endl;
        a[i/n][i%n] = s[i];
        cout << a[i/n][i%n] << ' ';
    }
    cout << endl << "Зашифровано: '";
    int i = n / 2, j = i, imax = i + 1, imin = i - 1, jmax = j + 1, jmin = j - 1;
    do{
        while (j != jmin)
            cout << a[i][j--];
        jmin--;
        while (i != imax)
            cout << a[i++][j];
        imax++;
        while (j != jmax)
            cout << a[i][j++];
        jmax++;
        while (i != imin)
            cout << a[i--][j];
        imin--;
        while (j != jmin)
            cout << a[i][j--];
    }while (i > 0 || j > 0);
    cout << "'\n";
    cin.get(); return 0;
}