ITPEC FE Subject B April 2026 Question 3
From the answer group below, select the correct answer to be inserted into blank in the program. Here, the array indexes start at 1.
The function distance receives integer arrays S and T of size n as arguments and returns the Manhattan distance of the two vectors that can be computed as ∑ni=1|Si − Ti| . Function abs, which is used by the function distance, returns the absolute value of an integer. Assume that n is 1 or greater.
Answer group
Explanation
p ← p + abs(S[i] - T[i]) — the Manhattan distance adds up the absolute difference of each coordinate pair.
The formula ∑ni=1|Si − Ti| maps onto the loop piece by piece:
- •∑ — accumulate into
pwith+on every pass of the loop - •|Si − Ti| — the absolute value of the difference of the two coordinates,
abs(S[i] - T[i])
Example: for S = {1, 5} and T = {4, 2}, p becomes 0 + 3 = 3, then 3 + 3 = 6.
Answer (b)
Why not others:
- •(a) — adds the coordinates instead of subtracting them; in the example it returns 5 + 7 = 12, which says nothing about how far apart the vectors are
- •(d) — subtracts each term from
p, returning the negative of the distance (−6 in the example); a distance cannot be negative - •(c) — makes both mistakes, adding the coordinates and subtracting the result from
p
Key rule: Translate a formula symbol by symbol: the summation becomes an accumulating + in the loop, the bars become abs, and the sign inside them stays as written.
Array Manipulation · AI-written, may contain errors
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