KMP模板

fail[i]=k表示B[0,k]=B[i-k,i];

void KMP(int B[],int m) {
	fail[0] = -1;
	for (int i = 1 , j = -1; i < m ; i ++) {
		while (j >= 0 && B[j+1] != B[i]) j = fail[j];
		if (B[j+1] == B[i]) j ++;
		fail[i] = j;
	}
}
bool match(int A[],int B[],int n,int m) {
	for (int i = 0 , j = 0 ; i < n ; i ++) {
		while (j > 0 && B[j] != A[i]) j = fail[j-1] + 1;
		if (B[j] == A[i]) j ++;
		if (j == m) return true;
	}
	return false;
}