The number of substrings (of all lengths inclusive) that can be formed from a character string of length n is:
A. n
B. n...

Question

The number of substrings (of all lengths inclusive) that can be formed from a character string of length n is:
A. n
B. n^2
C. n(n+1)/2
D. 2^n

Accepted Answer

n(n+1)/2 A substring is a contiguous block of characters defined by a starting position and a length. For a string of length n, substrings of length k can start at positions 1 through n-k+1, giving (n-k+1) such substrings. Summing over all lengths from 1 to n yields n + (n-1) + ... + 1, which is the triangular number n(n+1)/2.

The number of substrings (of all lengths inclusive) that can be formed from a character string of length n is: A. n B. n^2 C. n(n+1)/2 D. 2^n