55 WA,TLE,RE求助

#include<bits/stdc++.h>
using namespace std;
vector<int> x;
vector<int> y;
char f[105][105];
int a,b,c,d,nt=0,st=0;
int main(){
	cin>>b>>a>>d>>c;
	c=b-c+1; 
	for(int i=1;i<=a;i++){
		for(int j=1;j<=b;j++){
			cin>>f[i][j];
			if(f[i][j]=='*')st++;
		}
	}
	f[c][d]='M';
	x.push_back(c);
	y.push_back(d);
	while(1){
		
		if(a*b-st==x.size()){
			cout<<nt;
			break;
		}
		nt++;
		vector<int> x1;
		vector<int> y1;
		for(int i=0;i<x.size();i++){
			int X=x[i],Y=y[i];
			for(int v=X-1;v<=X+1;v++){
				for(int j=Y-1;j<=Y+1;j++){
					if(f[v][j]=='.'){
						f[v][j]='M';
						x1.push_back(v);
						y1.push_back(j);
					}
				}
			}
		}
		for(int i=0;i<x1.size();i++){
			x.push_back(x1[i]);
			y.push_back(y1[i]);
		}
	}
	return 0;
}