大红大紫 求调

#include<iostream>
#include<cmath>
using namespace std;
int n,m;
int tot[3001][3001];
char form[3001][3001];
int head=2,tail=1;
int flag[3001][3001];
int allow[2][900000];
int start_x,start_y,end_x,end_y;
int helpx[4]={0,0,-1,1};
int helpy[4]={1,-1,0,0};
int the_device_x;
int the_device_y;
void into(){
	cin>>n>>m;
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			cin>>form[i][j];
			if(form[i][j]=='#'){
				start_x=i;
				start_y=j;
			}
			if(form[i][j]=='='){
				end_x=i;
				end_y=j;
			}
		}
	}
}
void find_device(char adress,int x,int y){
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			if(form[i][j]==adress&&(x!=i||y!=j)){
				the_device_x=i;
				the_device_y=j;
				return ;
			}
		}
	}
}
bool if_device(int x,int y){
	if(form[x][y]>='A'&&form[x][y]<='Z'){
		return 1;
	}
	else{
		return 0;
	}
} 
int search(){
	allow[1][head]=start_x;
	allow[2][head]=start_y;
	while(head>=tail){
		for(int i=0;i<4;i++){
			if(form[allow[1][tail]+helpx[i]][allow[2][tail]+helpy[i]]!='#'){
				head++;
				if(if_device(allow[1][tail]+helpx[i],allow[2][tail]+helpy[i])){
					find_device(form[allow[1][tail]+helpx[i]][allow[2][tail]+helpy[i]],allow[1][tail]+helpx[i],allow[2][tail]+helpy[i]);
					allow[1][head]=the_device_x;
					allow[2][head]=the_device_y;
					tot[allow[1][tail]+helpx[i]][allow[2][tail]+helpy[i]]=tot[allow[1][tail]][allow[2][tail]]+1;
				}
				else if(form[allow[1][tail]+helpx[i]][allow[2][tail]+helpy[i]]=='='){
					return tot[allow[1][tail]][allow[2][tail]]+1;
				}
				else{
					allow[1][head]=allow[1][tail]+helpx[i];
					allow[2][head]=allow[2][tail]+helpy[i];
					tot[allow[1][tail]+helpx[i]][allow[2][tail]+helpy[i]]=tot[allow[1][tail]][allow[2][tail]]+1;
				}
			}
		}
		tail++;
	}
}
void outto(){
	cout<<search();
}
int main(){
	into();
	outto();
}