# 3.4. Exercises#

Many of these exercises are taken from past exams of APS105 Computer Fundamentals courses at University of Toronto. The solutions are provided in the answer boxes.

## 3.4.1. Conditional Statements#

### 3.4.1.1. Practice 1#

Question 2 in Winter 2018 Midterm Exam

Write a single C statement — which contains exactly one terminating semi-colon (;), and does not contain brace brackets ({ or }) — that declares a bool variable named isHighlighted, and sets its value to true if and only if the value stored in an integer variable named characterCount is an even positive number. Assume that the variable characterCount has already been declared and initialized.

### 3.4.1.2. Practice 2#

Question 2 in Winter 2019 Midterm Exam

Write a single C statement that declares a boolean-type variable named divisible and assigns true to divisible if and only if the value stored in the int variable named numOfItems is exactly divisible by $$5$$ or $$7$$. Assume that variable numOfItems has been declared and initialized.

### 3.4.1.3. Practice 3#

Question 7 in Winter 2018 Final Exam

Evaluate the following relational expressions by circling the right answer.

Expression

true / false

'\O' == 0

int x = 10 % 8;
(x > 0) && (x % 2 == 0) && !false

'c' - 3 == 'a'

int w = rand() % 75 * 2 - 99;
(w < -99) || (w > 49);

### 3.4.1.4. Practice 4#

Question 3 in Winter 2022 Midterm Exam

Suppose that x and y are int type variables, write a single C statement that is equivalent to the following statement, but is simpler, i.e. with fewer boolean and relational operators.

bool var = !(x <= y && y <= z);


## 3.4.2. Nested-if Statements#

### 3.4.2.1. Practice 1#

Modified version of Question 7 in Winter 2019 Midterm Exam

Write C program to find the median, which is the number at the middle, among three integers p, q and r. The program should prompt the user to enter three integers, which get stored in p, q and r. Your program should print the value of the number at the middle. For example, with integers $$2$$, $$7$$, and $$5$$ as input, the function returns 5; with integers $$6$$, $$4$$, and $$6$$ as input, the function returns $$6$$.

### 3.4.2.2. Practice 2#

Modified Version of Question 4 in Winter 2022 Midterm Exam

The following program finds the middle character, e.g., if we have a = 'a', b = 'b', and c = 'c', the program prints b. Rewrite this function such that it only uses one printf and one if statement.

int main(void) {
char a = '\0', b = '\0', c = '\0';
printf("Enter three characters: ");
scanf("%c %c %c", &a, &b, &c);
if (a < b) {
if (b < c) {
printf("%c", b);
} else if (a < c) {
printf("%c", c);
} else {
printf("%c", a);
}
}

if (c < b) {
printf("%c", b);
}
if (a < c) {
printf("%c", a);
}
printf("%c", c);
}