section5_exercises

Exercises

The 'if' statements

1. Write a program that reads a number and tells if it's odd or even.

Insert a number? 50
50 is even.

2. Write a program that asks the weight (Kg) and height (m) of a individual. Then calculate the Body Mass Index (BMI) and print the category according with the table below.

IBM = weight (kg) / heigth^2 (m)

Category	BMI (kg/m^2)
Severely underweight	[0,16)
Underweight	[16,18.5)
Normal	[18.5,25)
Overweight	[25,30)
Moderately obese	[30,35)
Severely obese	>= 35

Height ? 1.75
Weight ? 72

Normal

3. Write a program that calculates the roots of a second-degree polynomial.

💡 So far you are including stdio.h on your programs to use printf() and scanf(). To solve this exercise you need to calculate the square root of a number. You could implement your own algorithm, but there's a match library that has a function to calculate the square root of a number. Check the math.h library and particularly the sqrt() function. As a developer you need to see documentation all the time.

Enter the second degree polynomial coefficients (a*x^2 + b*x + c).

a ? 1
b ? 0
c ? -4
x = 2.000000  v  x = -2.000000

Enter the second degree polynomial coeficients (a*x^2 + b*x + c).

a ? 5
b ? 1
c ? 1
No real roots!

Enter the second degree polynomial coeficients (a*x^2 + b*x + c).

a ? 1
b ? 0
c ? 0
x = -0.000000

Loops

1. Write a program that reads a number and presents you the sum of its digits.

Number ? 75
The digits sum of 75 is 12.

Number ? 9
The digits sum of 9 is 9.

Number ? 205
The digits sum of 205 is 7.

2. Write a program to determine the prime factors of a number.

Number? 10
Factors: 2 5 

Number? 15
Factors: 3 5 

Number? 36
Factors: 2 2 3 3 

Number? 124
Factors: 2 2 31 

3. Write a program that takes in a number of grades from a class of students and determines the average grade.

Number of students? 3
Grade? 15
Grade? 16
Grade? 16
Average grade is 15.666667

Number of students? 5
Grade? 15
Grade? 10
Grade? 13
Grade? 14
Grade? 18 
Average grade is 14.000000

4. Write a program that reads out two integer values, let's call them N and K. Given a set of integers from [1, N], and considering 2 integers of this set, let's call them A and B, where A < B, find:
   • the maximum value of A & B which is less than K
   • the maximum value of A | B which is less than K
   • the maximum value of A ^ B which is less than K

Remember that these are bitwise operators:

• & - bitwise and
• | - bitwise or
• ^ - bitwise xor (exclusive or)

N? 5 
K? 4
Max a & b: 2
Max a | b: 3
Max a ^ b: 3