Practice Problem 4

Read it right next to your computer. Book version bitter C

learn through suffering C language learn through suffering
C language

Basics

Question 1-1

What is the term for a string enclosed in "" ?

Question 1-2

In mathematics, what symbol is used instead of the × symbol when writing in C?

Question 1-3

What symbol is used in C language instead of the division symbol ÷ in mathematics?

Question 1-4

What notation is used in C to represent floating-point numbers?

Program reading

How will the program be displayed when executed?

Question 2-1

#include <stdio.h>

int main(void)
{
    printf("%d\n", 20 / 7);
    printf("%f\n", 20.0 / 7.0);
    return 0;
}

Program Manual

Question 3-1

Create a program that calculates 40 ÷ 13 and displays the expression, quotient, and remainder.

explanatory

Question 4-1

In C, when performing integer division,
if the result cannot be divided evenly, it is truncated.
Explain concisely why this occurs.

Fundamentals (Answer Key)

Solution 1-1

String literal

Solution 1-2

※ Read as asterisk.

Solution 1-3

(※ Read as a slash.)

Solution 1-4

Floating-point

Program Reading (Solution Example)

Solution 2-1

2
2.857143

Please note that integer division truncates, rather than rounds.
For real number answers, accuracy to two decimal places is sufficient.
Question

Program Documentation (Example Solution)

Solution 3-1

#include <stdio.h>

int main(void)
{
    printf("%d / %d = %d ... %d\n", 40, 13, 40 / 13, 40 % 13);
    return 0;
}

Note that different symbols for division or remainder are also considered correct.
While displaying the expression as a string is also considered correct, using a format specifier (%d) is preferable.
Do not perform calculations; answers provided as strings will be marked incorrect.

Descriptive (answer example)

Solution 4-1

When rounding, performing the inverse calculation of quotient × divisor results in a value greater than the original dividend, creating a contradiction. Therefore, rounding down reduces contradictions and minimizes calculation errors.

About This Site

Learning C language through suffering (Kushi C) is
This is the definitive introduction to the C language.
It systematically explains the basic functions of the C language.
The quality is equal to or higher than commercially available books.

Part 0: Program Overview

What is a program?