Sequence Programming Problem

Question

Hi, Problem Statement

You have an infinite sequence A[] with the following properties: * A[0], A[1], ..., A[N-1] are given; * A[i]=(A[i-1]+A[i-2]+...+A[i-N])%10 for all i>=N;

Sequence B[] with length M is a substring of A[] if there is such index P that B[0]=A[P], B[1]=A[P+1], ..., B[M-1]=A[P+M-1]. Your task is to find the smallest possible such P. If there is no such index, return -1.

Constraints - A will contain between 1 and 7 elements, inclusive. - B will contain between 1 and 50 elements, inclusive. - Each element of A will be between 0 and 9, inclusive. - Each element of B will be between 0 and 9, inclusive.

Examples 0)

{1,2,3}

{0,7,8,5}

Returns: 5

Starting with 1,2,3 we have: 1+2+3 = 6, 6 % 10 = 6 2+3+6 = 11, 11 % 10 = 1 3+6+1 = 10, 10 % 10 = 0 6+1+0 = 7, 7 % 10 = 7 1+0+7 = 8, 8 % 10 = 8 0+7+8 = 15, 15 % 10 = 5 7+8+5 = 20, 20 % 10 = 0

1,2,3,6,1,0,7,8,5,0 0,7,8,5 answer = 5

1)

{1,2,8}

{7,4,2,3}

Returns: -1

2)

{1,2,3,4,5}

{4,5}

Returns: 3

3)

{1}

{1,1,1}

Returns: 0