Codility-Challenges

1. Integer Substrings: Write a function that, given two integers A and B, returns the leftmost position at which A occurs in B. The function should return -1 if A does not occur in B.
2. Increment Array: Write a function which returns an array which represents number X+1.
3. String Transformation: Write a function that, given a string S (containing only the letters 'A', 'B', and 'C') consisting of N characters, returns any string that can result from a sequence of transformations.
4. Calculate List lenght from Array: Write a function that, given a non-empty array A consisting of N integers, returns the length of the list constructed from A.