F题第31个样例过不去，请各位看一下我的代码。

#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<map>
#include<set>
#include<unordered_set>
#include<unordered_map>
using namespace std;

#define ull unsigned long long
#define ll long long
#define all(x) (x).begin(),(x).end()
const int N=1e6+10;

ull p[N],h[N],hb[N],base=133331;
int T,n;
string a,b;

ull cal(int l,int r){
	return h[r]-h[l-1]*p[r-l+1];
}
ull calb(int l,int r){
	return hb[r]-hb[l-1]*p[r-l+1];
}
void ini(){
	p[0]=1;
	for(int i=1;i<N;i++) p[i]=p[i-1]*base;
}
void solve(){
	string temp=a;
	reverse(a.begin()+1,a.end());
	for(int i=1;i<=n;i++){
		h[i]=h[i-1]*base+a[i]-'a';
		hb[i]=hb[i-1]*base+b[i]-'a';
	}
	vector<int> suf(n+2,0);
	for(int i=n;i>=1;i--){
		if(temp[i]==b[i]) suf[i]=1,suf[i]+=suf[i+1];
	}
	map<int,vector<int>> mp;
	for(int i=1;i<=n;i++){
		int l=i,r=n;
		while(l<=r){
			int mid=(l+r)/2;
			if(cal(i,mid)==calb(1,mid-i+1)) l=mid+1;
			else r=mid-1;
		}
		if(r<i){
			mp[0].push_back(n-i+1);
			continue;
		}
		int val=r-i+1;
		if(r==n) val+=suf[n-i+2];
		mp[val].push_back(n-i+1);
	}
	cout<<mp.rbegin()->first<<' '<<*min_element(all(mp.rbegin()->second))<<'\n'; 
	for(int i=1;i<=n;i++) h[i]=hb[i]=0;
}
int main(){
	ios::sync_with_stdio(false),cin.tie(0);
	
	ini();
	cin>>T;
	while(T--){
		cin>>n;
		cin>>a>>b;
		a=' '+a,b=' '+b;
		solve();
	}
	return 0;
}