fct spirala

#include <bits/stdc++.h>
using namespace std;
ifstream f("caroiaj.in");
ofstream g("caroiaj.out");
char a[501][501];
char s[250001];
int n, i, j, k, mx, p;
void spirala()
{
    int k, j, i;
    for(k = 1;k <= n / 2;k++)
    {
        for(j = k;j <= n - k + 1;j++)
            s[p++] += a[k][j];
        for(i = k + 1;i <= n - k + 1;i++)
            s[p++] += a[i][n - k + 1];
        for(j = n - k;j >= k;j--)
            s[p++] += a[n - k + 1][j];
        for(i = n - k;i > k;i--)
            s[p++] += a[i][k];
    }
    if(n % 2)
        s[p++] += a[n / 2 + 1][n / 2 + 1];
}