0 — Test 590

Correct Answer: B. Sentinel-controlled loop
Explanation: -1 is the sentinel (flag) value. A counter-controlled loop runs a known number of times.

Correct Answer: D. A condition that holds before the loop starts and remains true after every iteration
Explanation: Loop invariants are used to prove algorithms correct. For example, in insertion sort, the prefix a[0..i-1] is always sorted.

Correct Answer: A. 22
Explanation: i takes the values 1, 4, 7, and 10, and 1 + 4 + 7 + 10 = 22.

Correct Answer: C. 128
Explanation: i goes 1, 2, 4, ..., 64, and then 128. The loop stops at the first value that is not less than 100.

Correct Answer: C. 7
Explanation: i takes the values 1, 2, 4, 8, 16, 32, and 64, which is floor(log2 100) + 1 = 7 iterations. ALSO KNOW (related points): • How many times does the body of for (i = 10; i > 0; i -= 3) execute? → 4

Correct Answer: D. 10
Explanation: The inner loop runs 0 + 1 + 2 + 3 + 4 = 10 times.

Correct Answer: C. 10
Explanation: The code sums the digits: 4 + 3 + 2 + 1 = 10.

Correct Answer: D. 21
Explanation: Trailing zeros of the input become leading zeros of the result, and leading zeros disappear in an integer.

Correct Answer: D. Off-by-one: it accesses a[n], which is out of bounds
Explanation: The valid indices are 0 to n - 1, so the condition should be i < n.

Correct Answer: A. 11
Explanation: This is the classic fencepost (off-by-one) problem: there are 10 gaps, which need 11 posts. ALSO KNOW (related points): • Using Euclid's algorithm (repeated modulo), how many modulo operations does gcd(48, 18) take? → 3 • What is the final value of count?: count = 0; for i in range(1, 11):; if i % 2 == 0:; continue; count += i → 25