Computational Thinking · Quiz 1 · Jan 2026

This is a reference card showing the schemas and sample rows of Scores, Words, Library, Olympics and Shopping Bills. It supplies context for later pseudocode questions rather than asking for a computed result. Use the field names and row meanings when tracing the later algorithms; the displayed ellipses indicate omitted rows, not a complete dataset. **Answer: A.** A: **Correct:** The source selects the acknowledgement that useful dataset information is supplied. B: **Incorrect:** This describes its reference role too, but is not the source's selected administrative acknowledgement; these are not competing computational answers.

Mystery('M') visits every row but adds to count and sum only when X.Gender is M. sum accumulates the Physics scores of those male students, and count records their number. Returning sum/count therefore gives the male students' average Physics score, assuming at least one male student is present. **Answer: B.** A: **Incorrect:** Other genders are excluded by the condition. B: **Correct:** Filtered Physics sum divided by filtered student count gives this average. C: **Incorrect:** It neither sums total subject scores nor returns an undivided total. D: **Incorrect:** The Physics sum is divided by count before returning.

The surrounding condition already requires X.Total<AvgT. For that student, SubC starts at zero and increases separately for each subject whose mark is below its subject average. Exactly one such subject means SubC==1. If true, CountBA must increase by one, preserving the number counted from earlier rows. **Answer: D.** A: **Incorrect:** SubC<=1 also accepts students below average in zero subjects. B: **Incorrect:** Accepts zero as well as one and resets rather than accumulates CountBA. C: **Incorrect:** Tests the right subject count but overwrites CountBA with 1. D: **Correct:** Requires exactly one subject and increments the running student count.

Search for the row whose name equals S and test that same row's Total>180. B returns True immediately when both conditions hold, and False only after all rows have been searched without success. Distinct names ensure the matching student's row is unambiguous. **Answer: B.** A: **Incorrect:** Adds only Mathematics and Physics, omitting Chemistry from the intended total. B: **Correct:** Checks both the requested name and its complete total. C: **Incorrect:** Checks whether any student has a high total, ignoring S. D: **Incorrect:** Sums all students' totals rather than testing the specified student.

DoSomething counts vowels V in the current word of length N. The branches distinguish V<N/2, V=N/2, N/2<V<N, and V=N. Equivalently they group vowel proportions below one-half, equal to one-half, above one-half but below one, and equal to one. Thus the four tables are based on vowel-to-total-letter ratio. **Answer: C.** A: **Incorrect:** The tests depend on V relative to N, not on N alone. B: **Incorrect:** More/fewer vowels gives part of the classification but does not explain the separate all-vowel fourth group. C: **Correct:** Describes all four ratio-based categories. D: **Incorrect:** Only the last category consists exclusively of vowels; the other branches distinguish several other ratios.

The first pass maintains the three largest distinct bill amounts: First, Second and Third. The second pass must count every bill whose amount is at least Third, covering all bills at any of those three amount levels, including ties. Hence use X.TotalBillAmount>=Third and increment Count. The intended setup assumes nonnegative bill amounts and enough distinct amount levels for Third to represent a real third level. **Answer: D.** A: **Incorrect:** Counts bills below the third-highest threshold, the opposite region. B: **Incorrect:** Counts only the largest amount level. C: **Incorrect:** Strictly greater than Third leaves out bills at the third-highest level. D: **Correct:** Includes the largest, second-largest and third-largest amount levels, with ties.

A row contributes only if its shop is SV Stores and its total amount is strictly below 400. For each qualifying row the procedure adds its amount to sum and one to count. All other rows are ignored. Reordering does not change these mathematical sums and counts. sum/count, when count>0, is the mean only for the filtered bills, not all SV Stores bills. **Answer: A, B, D.** A: **Correct:** The shop-name condition excludes every other shop. B: **Correct:** The strict <400 test excludes amounts equal to or above 400. C: **Incorrect:** The same qualifying amounts are summed regardless of row order. D: **Correct:** Count increases once for every qualifying below-400 SV Stores bill. E: **Incorrect:** The computed mean excludes the store's bills of 400 or more, and is undefined if no bill qualifies.

To maintain a maximum, replace it only when a new qualifying bill is larger than the stored maximum. Step 5 instead tests max>amount, the reverse comparison. It should test ShopName=='Sun General' and amount>max. With nonnegative bill amounts, starting max at zero is appropriate. The remaining steps perform a normal full scan. **Answer: E.** A: **Incorrect:** A single input pile is a valid starting setup. B: **Incorrect:** Zero is a suitable initial bound for nonnegative bill amounts. C: **Incorrect:** Stopping on an empty pile is correct. D: **Incorrect:** Reading the top card is necessary. E: **Correct:** The maximum-update comparison is reversed. F: **Incorrect:** Moving the card and repeating ensures every card is processed once. G: **Incorrect:** Step 5 contains an actual error.

Each outer iteration removes one row X permanently from the remaining comparison pool. The inner loop compares X with every row still in Table1, moving those rows temporarily to Table3 and then restoring them. Thus each pair of distinct students is compared once: whichever student is selected earlier is X for that pair. DoSomething contributes 1 precisely for equal city and total. The final count is the number of matching unordered pairs and is invariant under input order. **Answer: B, C.** A: **Incorrect:** Ordered pairs would count both directions; this scan counts each pair once. B: **Correct:** Every matching unordered pair contributes exactly once. C: **Correct:** X has already left Table1, so the inner loop cannot compare X with itself. D: **Incorrect:** Changing order changes which direction is visited, not how many matching pairs exist.

A word contributes 3 when consonants outnumber vowels, otherwise 1. Ignore case and treat the terminal full stop as punctuation rather than a letter. The (vowels,consonants) counts are patience (4,4), and (1,2), persistence (4,7), often (2,3), unlock (2,4), hidden (2,4), potential (4,5). Only patience fails the strict greater-than test. Thus Score=1+6×3=19. Equal counts go into the else branch. **Answer: 19.**