HDU 1711 Number Sequence——kmp

模板题

#include <cstdio>
using namespace std;
const int maxn = 1e6 + 10;
int t, n, m, T[maxn], P[maxn], fail[maxn];
void Getfail() {
fail[0] = 0;
for (int i = 1, j = 0; i < m; i++) {
while (j && P[i] != P[j]) j = fail[j - 1];
if (P[i] == P[j]) j++;
fail[i] = j;
}
}
int Search() {
Getfail();
for (int i = 0, j = 0; i < n; i++) {
while (j && T[i] != P[j]) j = fail[j - 1];
if (T[i] == P[j]) j++;
if (j == m) return i - j + 2;
}
return -1;
}
int main() {
scanf("%d", &t);
for (int kase = 1; kase <= t; kase++) {
scanf("%d %d", &n, &m);
for (int i = 0; i < n; i++) scanf("%d", &T[i]);
for (int i = 0; i < m; i++) scanf("%d", &P[i]);
printf("%d\n", Search());
}
return 0;
}