Algorithms with Selection and Repetition Practice Test

A school stores grades in an int[] gradeList; the algorithm iterates to compute average and count grades >= threshold. Inputs are gradeList and threshold; outputs are average and countAbove. Example input: 80, 90, 70, threshold 85; output: average 80.0, countAbove 1. Example input: 100, 60, threshold 70; output: average 80.0, countAbove 1.

// Compute average and count grades at or above threshold

int sum = 0;

int countAbove = 0;

for (int i = 0; i < gradeList.length; i++) {

    sum += gradeList<u>i</u>;

    if (gradeList<u>i</u> >= threshold) {

        countAbove++;

    }

}

double average = (double) sum / gradeList.length;

System.out.println(average + "," + countAbove);

Consider the algorithm for processing grades; which part ensures every grade is compared to threshold exactly once?

A guessing game picks a secret integer; the player repeatedly guesses until correct. Inputs are secret and a sequence of guesses; output is the number of attempts and feedback messages. Example input: secret 7, guesses 3,9,7; output: "Too low", "Too high", attempts 3. Example input: secret 2, guesses 2; output: attempts 1.

int attempts = 0;

int guess = -1;

while (guess != secret) {

    guess = getNextGuess();

    attempts++;

    if (guess < secret) {

        System.out.println("Too low");

    } else if (guess > secret) {

        System.out.println("Too high");

    }

}

System.out.println("Attempts: " + attempts);

Consider the algorithm for the guessing game; why is a loop necessary in this part of the algorithm?