1 #include<stdio.h>
2 #include<string.h>
3 int a[1000005],b[1000005],next[100005];
4 int main()
5 {
6 int t,i,j,n,m;
7 while (~scanf("%d",&t))
8 while (t--)
9 {
10 scanf("%d%d",&n,&m);
11 for (i=1;i<=n;i++) scanf("%d",&a[i]);
12 for (i=1;i<=m;i++) scanf("%d",&b[i]);
13 //先求next数组
14 i=1; next[1]=0; j=0;
15 while (i<=m)
16 {
17 if (j==0||b[i]==b[j]) {i++; j++;
18 if (b[i]!=b[j]) next[i]=j; else next[i]=next[j]; }
19 else j=next[j];
20 }
21 //KMP
22 i=1; j=1;
23 while (i<=n&&j<=m)
24 {
25 if (j==0||a[i]==b[j]) {i++; j++; }
26 else j=next[j];
27 }
28 //OK
29 if (j>m) printf("%d\n",i-m);
30 else printf("-1\n");
31 }
32 return(0);
33 }
http://acm.hdu.edu.cn/showproblem.php?pid=1711
