我的代码虽然AC了，但是我判断他们不会相遇的条件是不正确的，求大犇帮帮改一下我的不会相遇的条件

#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long timing;
typedef int place;
typedef int toward;
char a[12][12];
timing t=0;
place xc,yc,xf,yf;//x：在第几行，y：在第几列
void c_change(place &xc,place &yc,toward &cd)
{
	toward numc=cd%4;
	if(numc==1){
		if(a[xc-1][yc]=='*'){
			cd++;
		}else swap(a[xc][yc],a[xc-1][yc]),xc--; 
	}
	if(numc==2){
		if(a[xc][yc+1]=='*'){
			cd++;
		}else swap(a[xc][yc],a[xc][yc+1]),yc++;
	}
	if(numc==3){
		if(a[xc+1][yc]=='*'){
			cd++;
		}else swap(a[xc][yc],a[xc+1][yc]),xc++;
	}
 	if(numc==0){
	 	if(a[xc][yc-1]=='*'){
		 	cd++;
		}else swap(a[xc][yc],a[xc][yc-1]),yc--;
	}
}
void f_change(place &xf,place &yf,toward &fd)
{
	toward numf=fd%4;
	if(numf==1){
		if(a[xf-1][yf]=='*'){
			fd++;
		}else swap(a[xf][yf],a[xf-1][yf]),xf--;
	}
	if(numf==2){
		if(a[xf][yf+1]=='*'){
			fd++;
		}else swap(a[xf][yf],a[xf][yf+1]),yf++;
	}
	if(numf==3){
		if(a[xf+1][yf]=='*'){	
			fd++;
		}else swap(a[xf][yf],a[xf+1][yf]),xf++;
	}
 	if(numf==0){
	 	if(a[xf][yf-1]=='*'){
		 	fd++;
		}else swap(a[xf][yf],a[xf][yf-1]),yf--;
	}
}
int main()
{
	ios::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
	toward cd=1,fd=1;
	for(int i=0;i<=11;i++){
		for(int j=0;j<=11;j++){
			a[i][j]='*';
		}
	}
	for(int i=1;i<=10;i++){
		for(int j=1;j<=10;j++){
			cin>>a[i][j];
			if(a[i][j]=='C') xc=i,yc=j;//牛的位置
			if(a[i][j]=='F') xf=i,yf=j;//农场主的位置
		}
	}
	while(xc!=xf||yc!=yf){
		c_change(xc,yc,cd);
		f_change(xf,yf,fd);		
		t++;
		if(t>=2000){//就是这个
			cout<<0;
			return 0;
		}
	}
	cout<<t;
	
	
	
	
	
	
	
	
	
	return 0;
}