80pts求条

#include<bits/stdc++.h>
using namespace std;
int main(){
	int t,n,m;
	string s1,s2;
	cin>>t;
	for(int e=1;e<=t;e++){
		cin>>n>>m;
		cin>>s1>>s2;
		if(n>m){cout<<"No"<<endl;continue;}
		if(s1==s2){cout<<"Yes"<<endl;continue;}
		int ansi=-1,ansj=-1;
		for(int i=0;i<n;i++)
			if(s1[i]!=s2[i]){ansi=i;break;}
		for(int i=1;i<=n;i++)
			if(s1[n-i]!=s2[m-i]){ansj=i;break;}
		if(ansi+ansj-1==n||ansi==-1||ansj==-1) cout<<"Yes"<<endl;
		else cout<<"No"<<endl;
	}
	return 0;
}