COVUA C++

#include <bits/stdc++.h>
using namespace std;

int a[15][15];
int h[9]={0,-2,-1,1,2,2,1,-1,-2};
int c[9]={0,1,2,2,1,-1,-2,-2,-1};

int x1,yk,x2,y2;

void nhap()
{
    char c;
    cin>>c;
    yk=int(c)-96;
    cin>>x1;
    x1=9-x1;
    //cout<<x1<<" "<<yk<<endl;
    cin>>c;
    y2=int(c)-96;
    cin>>x2;
    x2=9-x2;
    //cout<<x2<<" "<<y2<<endl;
}

void quan_xe_an()
{
    for(int i=1;i<=8;i++)
    {
        a[x1][i]=1;
        a[i][yk]=1;
    }
}

void quan_ma1_an()
{
    for(int i=1;i<=8;i++)
    {
        if(x2+h[i]>=0&&y2+c[i]>=0)
            a[x2+h[i]][y2+c[i]]=1;
    }
}

void quan_ma2()
{
    for(int i=1;i<=8;i++)
    {
        if(x1+h[i]>=0&&yk+c[i]>=0)
            a[x1+h[i]][yk+c[i]]=1;
    }
}


void xuli()
{
    a[x1][yk]=1;
    a[x2][y2]=1;
    quan_xe_an();
    quan_ma1_an();
    quan_ma2();
    int d=0;
    for(int i=1;i<=8;i++)
        for(int j=1;j<=8;j++)
            if(a[i][j]==0) d++;
    cout<<d;
}