蒟蒻求助！86分代码就差这一个测试点啦

测试点2信息:
输入:

5
-@@@-
-@@--
-@---
-----
-----
-----
----@
---@@
--@@@
-----

期待输出：

5

我的输出：

7

本人代码如下

#include <bits/stdc++.h>
using namespace std;
int n;
char a[15][15],b[15][15],c[15][15],d[15][15];
void give_b_to_a(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            a[i][j] = b[i][j];
}
void give_a_to_d(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            d[i][j] = a[i][j];
}
void give_d_to_a(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            a[i][j] = d[i][j];
}
void give_a_to_b(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            b[i][j] = a[i][j];
}
bool check_bc(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            if (b[i][j] != c[i][j])
                return 0;
    return 1;
}
bool f1(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            b[n-j+1][i] = a[i][j];
    return check_bc();
}
bool f2(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            b[n+1-i][n+1-j] = a[i][j];
    return check_bc();
}
bool f3(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            b[n-i+1][n-j+1] = a[i][j];
    return check_bc();
}
bool f4(){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            b[i][n-j+1] = a[i][j];
    return check_bc();
}
bool f5(){
    f4();
    give_b_to_a();
    if (f1()||f2()||f3()) {
        give_d_to_a();
        return 1;
    }
    give_d_to_a();
    return 0;
}
bool f6(){
    give_a_to_b();
    return check_bc();
}
void conclusion(){
    if (f1())  cout << 1;
    else if (f2()) cout << 2;
    else if (f3()) cout << 3;
    else if (f4()) cout << 4;
    else if (f5()) cout << 5;
    else if (f6()) cout << 6;
    else cout << 7;
}
int main(){
    string s;
    cin >> n;
    getline(cin,s);
    for (int i = 1; i <= n; i++){
        getline(cin,s);
        for (int j = 0; j < n; j++){
            a[i][j+1] = s[j];
        }
    }
    for (int i = 1; i <= n; i++){
        getline(cin,s);
        for (int j = 0; j < n; j++){
            c[i][j+1] = s[j];
        }
    }
    conclusion();
    return 0;
}

本蒟蒻的思维和自己的代码一样，都觉得测试点2是无法通过组合变换得到的，没有理解题目的意思，希望大佬给出解释，并指点一下代码优化, 谢谢！