# LOOPS - EXAMPLES (C, C++, JAVA)

## Introduction to Loops in Programming

**Loops in the C/C++ programming language**

**Loops in JAVA**

## When to use different types of loops

**For loop:**Best used when you know in advance how many times you want to repeat a block of code. For example, to iterate through a known number of elements in an array or list.**While loop**: Used when the number of iterations is not known, but depends on a condition that can be changed inside the loop. It is ideal for situations when you work with uncertain inputs or events.

## Edge cases: Specific conditions and exceptional situations

**Infinite loop:**A loop that never ends, can happen if the condition never becomes false.

For example:

**while (true) {**

// Infinite loop

}

// Infinite loop

}

**Solution:**Make sure the condition is correct or add a break to avoid problems.

**Empty loop:**A loop that does not perform any action:

**for (int i = 0; i < 100; i++) {**

// Empty loop

}

// Empty loop

}

### 1. The club you support

### 2. Printing a sequence of numbers

### 3. Writing numbers by rows and columns

Set the initial value of the control variable to 1, as the first odd number of the required number interval, and to change the control variable, set it to change by 2. That is. the third expression in the for loop should be i=i+2

After printing the number, using the if statement, put a new line, if the current number is divisible by 10

{

if(ciklus % 10 == 0)

printf("\n");

}

### 4. Celsius to Fahrenheit

**Example 1***Input*

10

15

*Output*

10[C] 50[F]

11[C] 51.8[F]

12[C] 53.6[F]

13[C] 55.4[F]

14[C] 57.2[F]

15[C] 59[F]

First enter the values of temperatures c1 and c2 using the ** cin** command (C++) or scanf, and then create a for loop.

Put the control variable c, changes from c1 to c2 and it actually represents the temperature in Celsius.

In the body of the for loop, first calculate the current value in Fahrenheit using the formula:

T[^{o}F]=T[^{o}c]*9/5+32

Second, print these two values on the same line

using namespace std;

int main()

{

cin << c1 << c2;

/*Control variable c(temperature in Celsius) c changes from start c1 to end c2 with step 1

*/

for(double c=c1; c<=c2; c=c+1)

{

f=c*9.0/5.0+32;

cout << c << "[C] " << f << "[F]"<<endl;

### 5. Add even numbers

### 6. Average rating

### 7. Removing zeros from the right

### 8. Dividing a number with the same divisor

*and the divisor d. Abbreviate the number*

**N****with the divisor d as long as possible. Print the remainder as well as the number of cycles on the output. For example. Input: N=36, d=3; Output: 4 2;**

*N*

**Explanation**: 1st cycle: 36/3=12, 2nd cycle: 12/3=4, the remainder is 4 and the number of cycles is 2

### 9. Training

*kilometers during the first day. Determine how much he will run each day during n days of preparation, if it is known that he will run 10% more every next day than the previous one. Determine how many kilometers the athlete ran in total during the preparation.*

**X**### 10. Cost sheet

### 11. Free fall simulation

*. Enter the initial height of the body and create a loop where the time changes by*

**H0****0.05**seconds in each cycle. Write down all the current positions and velocities of the body at those moments in time during the fall. Determine the speed of the body when falling to the ground computationally and compare it with the value obtained by simulation.

### 12. Interest

**The initial amount of money, the percentage of annual interest attributed to that sum, and the number of years n are loaded. Calculate what the sum of money will be after 1, 2,... ,n years. Each year, interest is credited to the amount received at the end of the previous year.**

*Input*

The initial amount of money, the amount of annual interest in percentages, and the number of years for which the amount of money with interest should be written.

*Output*

In the ith line, write the amount of money after i years.

### 13. The meeting of two cars

Simulate this movement for the entered car speeds, so that every

**0.05s**of movement, the current time, the traveled paths of both cars, and the current distance between them are printed. The distance between places A and B is entered by the user.

Set a meeting time.

### 14. Ski jumps - average

### 15. Stock market

**A stock market trader either made a profit or lost money every day during one working week. Of all the days on which he earned something, determine the day on which he earned the least and the value he earned on that day (if there are more such days, report first) or report that he lost money on all days.**

*Input*

From the standard input, 5 integers from the interval [−10000,10000][−10000,10000] (amounts that the trader made on Monday, Tuesday, Wednesday, Thursday and Friday) are entered, each in a separate row.

*Output*

If the trader made a profit on a certain day (the amount is strictly greater than zero), on the standard output, in the first line, write the smallest amount of profit that was made during the week and in the second line, the designation of the day (MON, TUES, WED, CET or FRI) in which the smallest profit was achieved. If no earnings were made on any day, print a line containing only the character -.

**Example 1***Input*

3200

-420

-10

1350

5670

*Output*

1350

CET

**Example 2***Input*

-4700

-360

-1000

-1550

-3245

*Output*-

### 16. Countdown

*petlja.org/biblioteka/r/Zbirka/brojevi_obrnuti_redosled*

Write a program that counts down from a given number to zero.

### 17. Show announcements

**petlja.org:**petlja.org/biblioteka/r/problemi/Zbirka/najave_emisije_u_pravilnim_intervalima

**The beginning and end of a movie is known (time in hours and minutes). At regular time intervals, first at the beginning of the movie and then after every mm minutes, an announcement of the next show is shown in the corner of the screen. Write a program that prints the times at which this announcement is shown.**

**Input**

The standard input contains the start time of the movie given in the form of two integers, each in a separate line representing the number of hours and the number of minutes, then, in the next line, the end time of the movie given in the same form and finally one integer representing the interval in minutes in which the announcement is displayed.

**Output**

On the standard output, display the broadcast times of the announcement in the form of h:m, each in a separate line.

**Example***Input*

12

0

13

53

15

*Output*

12:0

12:15

12:30 p.m

12:45

13:0

13:15

13:30

3:45

### 18. Read to the end of the entry

****

**Task from the site**

*petlja.org/biblioteka/r/problemi/Zbirka/citanje_do_kraja_ulaza*Whole numbers are entered from the input until the end of the input is reached. Write a program that displays how many numbers have been entered.

**Input**

Each line of standard input contains one integer. NOTE: when testing the program interactively, the end of the standard input is marked with the ctrl + z key combination if the Windows operating system is used, i.e. ctrl + d if using Linux operating system.

**Output**

In the first line of standard output, show how many numbers have been entered.

**Example***Input*

20

145

-23

12

456

13

*Output*

6

### 19. Reading the grades to the end of the entry and calculating the average

**From the entrance, grades from a subject are entered until the end of the entrance is reached. Write a program that displays the average grade.**

**Input**

Each line of standard input contains an integer representing a rate.

**Output**

Display the average grade in the first line of standard output.

**Example***Input*

5

2

4

4

2

6

*Output*

3.83

### 20. Juice warehouse

**Input**

In the first line of the standard input there is a natural number n (1≤n≤100) which represents the number of shelves in the warehouse. In the second, there is a natural number k (5≤k≤30) which represents the capacity of the crate. In each of the following nn lines there is a natural number, from the interval [5,500], which represents the number of bottles on each shelf.

**Output**

The smallest number of used crates is printed in one line of the standard output.

**Example***Input*

3

8

31

25

16

*Output*

10

### 21. The cheapest for a dinar

**Input**

From the standard input, three integers from the interval from 50 to 5000 are entered, which represent the prices in dinars for the three purchased products.

**Output**

Print an integer representing the total discounted price of those three products to standard output.

**Example***Input*

2499

3599

899

*Output*

6099

### 22. Broadcast announcements at regular time intervals

**The beginning and end of a movie is known (time in hours and minutes). At regular time intervals, first at the beginning of the movie and then after every mm minutes, an announcement of the next show is shown in the corner of the screen. Write a program that prints the times at which this announcement is shown.**

*Input*

The standard input contains the start time of the movie given in the form of two integers, each in a separate line representing the number of hours and the number of minutes, then, in the next line, the end time of the movie given in the same form and finally one integer representing the interval in minutes in which the announcement is displayed.

*Output*

On the standard output, display the broadcast times of the announcement in the form of h:m, each in a separate line.

**Example***Input*

12

0

13

53

15

*Output*

12:0

12:15

12:30 p.m

12:45

13:0

13:15

13:30

13:45

### 23. Reading to minus 1 or to the n-th

**Task from the site**

*petlja.org/biblioteka/r/problemi/Zbirka/citanje_do_minus_1_ili_do_ntog***During the lesson, Pera played and cut paper squares. The teacher noticed this and gave him the task of calculating the total area of all the squares. Write a program that helps Perry do this. Pera, at the very beginning, enters the number "n" which he is sure is greater than or equal to the number of squares. After that, he enters at most n numbers that represent the lengths of the sides of the squares, and if he notices that there are fewer squares than the number of n, he enters −1, which indicates that the entry needs to be stopped.**

******Input**

The number n (0≤n≤15) is loaded from the standard input, followed by 1≤m≤n integers between 11 and 1010, where, if m<n, then −1 is entered after them.

**Output**

Print a single integer representing the total area of all the squares to the standard output.

**Example 1***Input*

5

1

2

3

4

5

*Output*

55

**Example 2***Input*

5

1

2

3

-1

*Output*

14

### 24. Savings in the bank

### 25. Monthly earning

### 26. Target shooting

### 27. The salt concentration

### 28. The number of k-element variations of n elements without repetition

### 29. The multiplication table

1 * 1 = 1

1 * 2 = 2

...

9 * 8 = 72

9 * 9 = 81

### 30. The Least Common Multiple

**Additional examples for exercise - branching in the program**