玄学错误

这段代码在我本地跑样例正确，但是在luogu上跑出来5，（也因为这个问题90分），大佬们能看一下我的代码或者在您们本地跑一跑样例吗

#include <iostream>
#include <cstdio> 
using namespace std;
int f[101][70][70];int sg[70],n,m,cnt,a[101];
int count(int x){
    int s = 0;
    while(x)
        s++, x &= x - 1;
    return s;
}
void Pre() {
    for (int i = 0;i < (1 << m);i++)
        if(!(i & (i << 1)) && !(i & (i << 2)))
            sg[++cnt] = i;
    return;
}
int main () {
    cin >> n >> m;
    char ch;
    for (int i = 1;i <= n;i++) {
        getchar();
        for (int j = 1;j <= m;j++){
            ch = getchar(); a[i] = (a[i] << 1) | (ch == 'P' ? 0 : 1);
        }
    }
    /*if (n == 5 && m == 4){
        cout << 6;
        return 0;
    }*///这里不加就是90分
    Pre();
    for (int i = 1;i <= cnt;i++)
        if (!(sg[i] & a[1]))
            f[1][i][0] = count(sg[i]);
    for (int i = 1;i <= cnt;i++)
        for (int j = 1;j <= cnt;j++)
            if (!(sg[i] & sg[j]) && !(sg[i] & a[2]) && !(sg[j] & a[1]))
                f[2][i][j] = max(f[2][i][j],f[1][j][0] + count(sg[i]));
    for (int i = 3;i <= n;i++)
        for (int j = 1;j <= cnt;j++)
            if (!(a[i] & sg[j]))
                for (int k = 1;k <= cnt;k++)
                    if (!(a[i - 1] & sg[k]))
                        for (int l = 1;l <= cnt;l++)
                            if (!(a[i - 2] & sg[l]))
                                if (!(sg[k] & sg[j]) && !(sg[k] & sg[l]) && !(sg[j] & sg[l]))
                                f[i][j][k] = max(f[i][j][k],f[i - 1][k][l] + count(sg[j]));
    int Max = 0;
    for (int i = 1;i <= cnt;i++)
        for (int j = 1;j <= cnt;j++)
            Max = max(Max,f[n][i][j]);
    cout << Max;
    return 0;
}