簡單的KMP，不解釋。

#include <map>
#include <set>
#include <list>
#include <queue>
#include <deque>
#include <stack>
#include <string>
#include <time.h>
#include <cstdio>
#include <math.h>
#include <iomanip>
#include <cstdlib>
#include <limits.h>
#include <string.h>
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;

#define LL long long
#define MIN INT_MIN
#define MAX INT_MAX
#define PI acos(-1.0)
#define FRE freopen("input.txt","r",stdin)
#define FF freopen("output.txt","w",stdout)
#define N 50005
int a[1000005],b[10005];
int p[10005];
int n,m;
void gao () {
    int i,j = 0;
    p[1] = 0;
    for (i = 2; i <= m; i++) {
        while (j > 0 && b[j+1] != b[i]) {
            j = p[j];
        }
        if (b[i] == b[j+1]) j++;
        p[i] = j;
    }
}
void kmp () {
    int i,j = 0;
    for (i = 1; i <= n; i++) {
        while (j > 0 && b[j+1] != a[i]) {
            j = p[j];
        }
        if (b[j+1] == a[i]) j++;
        if (j == m) {
            printf("%d\n",i - m +1 );
            return ;
        }
    }
    printf("%d\n",-1);
}
int main () {
    int t;
    scanf("%d",&t);
    while (t--) {
        scanf("%d%d",&n,&m);
        int i,j;
        for (i = 1; i <= n ;i++) scanf("%d",&a[i]);
        for (i = 1; i <= m; i++) scanf("%d",&b[i]);
        gao();
        kmp();
    }
    return 0;
}