【KMP求字符串第一个匹配位置】hdu 1711

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<stack>
#include<queue>
#include<deque>
#include<map>
#include<algorithm>
using namespace std;
typedef long long LL;
//#pragma comment(linker, "/STACK:102400000,102400000")
/*
hdu 1711 KMP简单题
求模式串第一次出现在目标串的位置
*/
const double PI = acos(-1.0);
const double eps = 1e-6;
const int INF=0x3f3f3f3f;
const int mod = 1e9+7;
const int N=1000010;

int a
,p
;
int net
;
void getnext(int len)
{
net[0] = -1;
int k = -1;
for(int i = 1; i < len; i++)
{
while(k!=-1 && p[k+1]!=p[i])
k = net[k];
if(p[k+1]==p[i])
k++;
net[i] = k;
}
}
int main()
{
int T;
scanf("%d",&T);
while(T--)
{
int n,m;
scanf("%d%d",&n,&m);
for(int i = 0; i < n; i++)
scanf("%d",&a[i]);
for(int i = 0; i < m; i++)
scanf("%d",&p[i]);
getnext(m);
int id = -1, k = -1;
for(int i = 0; i < n; i++)
{
while(k!=-1 && p[k+1]!=a[i])
k = net[k];
if(p[k+1]==a[i])
k++;
if(k == m-1)
{
id = i;
break;
}
}
if(id==-1)
puts("-1");
else
printf("%d\n",id-m+2);
}
return 0;
}