直接拿吧，AC的

给个关注吧

#include <iostream>
using namespace std;
int a[10][10];
int n,m,x,y,count=0;
int fd[2][8]={
	{-2,-2,-1,-1,1,1,2,2},
	{1,-1,2,-2,2,-2,1,-1}
};
int step=0;
void dfs(int h,int l){
	if(step==n*m){
		count++;
	}else{
		for(int i=0;i<8;i++){
			int nh,nl;
			nh = h+fd[0][i];
			nl = l+fd[1][i];
			if(a[nh][nl]==0&&nh>=0&&nh<n&&nl>=0&&nl<m){
				a[nh][nl]=1;
				step++;
				dfs(nh,nl);
				a[nh][nl] = 0;
				step--;
			}
		}
		
	}
}
int main(){
	int t;
	cin >> t;
	for(int i=0;i<t;i++){
		cin >> n >> m >> x >> y;
		a[x][y] = 1;
		step++;
		dfs(x,y);
	}
	cout << count;
	return 0;
}
//拿吧别客气