广搜做，第三个测评输出八位乱码

#include <bits/stdc++.h>
using namespace std;
string pre[7],res[7],a,b;
int n=1;
struct node{
	string s;int step;
}start;
queue<node> q;
int bfs(node x){
	q.push(x);
	while(!q.empty()){
		node xx=q.front();
		q.pop();
		if(xx.s==b){
			return xx.step;
		}
		if(xx.step>10) return 0; 
		for(int i=1;i<n;i++){
			int pos=xx.s.find(pre[i]);
			if(pos==-1)	continue;
			xx.s.replace(pos,pre[i].size(),res[i]);
			xx.step++;	
			q.push(xx);
		}
	}
}
int main(){
	cin>>a>>b;
	while(cin>>pre[n]>>res[n]){
		n++;
	}
	start.s=a;
	start.step=0;
	if(!bfs(start)){
		cout<<"NO ANSWER!";
		return 0; 
	}
	cout<<bfs(start);
}