ITPEC FE Morning April 2019 Question 8

String Concatenation via Character Arrays — copying two character arrays X (length m) and Y (length n) into a single array Z.

The algorithm uses two sequential loops:

• •Loop 1 (k: 1 to m): copies each character of X into the beginning of Z → X(k) → Z(k)
• •Loop 2 (k: 1 to n): copies each character of Y into Z starting after X → Y(k) → Z(m+k)

The key insight is the offset: Y's characters must start at position m + 1 in Z, so the index is m + k where k runs from 1 to n.

Why not others:
- (b) Uses Z(n+k) in B — offsets by n (Y's own length) instead of m (X's length), placing Y in the wrong position
- (c) Swaps the source arrays — copies Y first in Loop 1 and X in Loop 2
- (d) Same swap as (c), and also uses Z(n+k) instead of Z(m+k)

Key rule: When concatenating arrays, the second array's offset in the result equals the length of the first array.

AI-generated — may contain errors