Consider the problem of counting, in a given text, the number of substrings that start with an A and end with a B. For example, there are four such substrings in CABAAXBYA. a. Design a brute-force...

Consider the problem of counting, in a given text, the number of substrings that start with an A and end with a B. For example, there are four such substrings in CABAAXBYA.
a. Design a brute-force algorithm for this problem and determine its efficiency class.
b. Design a more efficient algorithm for this problem with complexity O (n)