hdu-1711（hash）

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
typedef long long ll;
const ll mod=1e9+7;
const ll p=133331;
const int M=1e6+100;
const int N=1e4+100;
ll h[M];
ll a[N],b[M];
ll lena,lenb,t,n,m;
ll pp[N];
ll juage(ll l,ll r)
{
    ll tmp=(h[r]-(h[l-1]*pp[r-l+1])%mod)%mod;
    while(tmp<0)
        tmp+=mod;
    return tmp;
}
int main()
{
    cin>>t;
    while(t--)
    {
        memset(h,0,sizeof(h));
        cin>>m>>n;
        ll ans=0;
        pp[0]=1;
        for(int i=1;i<=n;i++)
            pp[i]=(pp[i-1]*p)%mod;
        for(int i=1;i<=m;i++)
        {
            cin>>b[i];b[i]+=1000000;
            h[i]=(h[i-1]*p+b[i])%mod;
        }
        for(int i=1;i<=n;i++)
        {
            cin>>a[i];a[i]+=1000000;
            ans=(ans*p+a[i])%mod;
        }
        int sc=-1;
        for(int i=1;i<=m;i++)
        {
            if((i+n-1)>m)
                break;
            else
            {
               // cout<<i<<" "<<i+n-1<<" "<<juage(i,i+n-1)<<endl;
                if(juage(i,i+n-1)==ans)
                {
                    sc=i;break;
                }
            }
        }
        cout<<sc<<endl;
    }
}