Answer: "N" is considered as the size of the input that is being given in the algorithm.
Explanation: During a problem solving process , a algorithm is used to analyze the problem . Many function and steps are to be taken care of while analyzing algorithm. Among analyzing step, input is also given which is usually zero more than that . An input has a certain size which is given by the initial "N". The input size defines the length of the string for the input.
