Once you begin to tasks, therefore already know what for loop. Let's look at a few of the tasks, solution in which it is applied, and, thereby, strengthen the knowledge gained. Programming practice– the best way to deal with the material and store information for a long time.
1. Write a program, that will show on the screen the number of the square, entered by the user. The user has to decide for himself – exit the program or continue writing. (Tip – You must run an infinite loop, which provide for termination of his, upon the occurrence of certain conditions).
Show code
Задача: оператор for 1
C++
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#include <iostream>
usingnamespacestd;
intmain()
{
setlocale(LC_ALL,"rus");
intdigit=0;// число для расчета
charexit='y';// для выхода или продолжения
for(;;)
{
cout<<"Введите число: ";
cin>>digit;
cout<<"Квадрат "<<digit<<" = "<<digit*digit;
cout<<"\nПродолжить ввод чисел - Y, Выйти - N: ";
cin>>exit;// выбор пользователя
if(exit!='y'&&exit!='Y')
break;// прервать цикл
}
return0;
}
В задаче, as you can see, provided for continuation of the work, вне зависимости в каком регистре введена буква Y (в нижнем или в верхнем).
Result:
2. In the gym every day comes a certain number of visitors. It should prompt the user to enter such data: how many people visited the gym for the day, enter the age of each visitor and ultimately show the age of the oldest and the youngest of them, as well as to calculate the average age of visitors.
Show code
Задача: оператор for 2
C++
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#include <iostream>
usingnamespacestd;
intmain()
{
setlocale(LC_ALL,"rus");
intage=0;// будет вводить пользователь
intmaxAge=0;// для записи максимального количества лет
intminAge=100;// для записи минимального количества лет
intsum=0;// общая сумма для расчета среднего
intaverage=0;// для записи среднего возраста посетителей
intamount=0;// количество посетителей спортзала
cout<<"Введите количество посетителей спортзала: ";
cin>>amount;
for(inti=0;i<amount;i++)
{
cout<<"Введите возраст "<<i+1<<"-го посетителя: ";// запрос на введение числа
cin>>age;
if(age>maxAge)// если оно больше, чем хранит переменная max
maxAge=age;// записываем в неё это число
if(age<minAge)
minAge=age;
sum+=age;// накопление общей суммы
}
average=sum/amount;// подсчет среднего возраста
cout<<"\nСредний возраст всех посетителей: "<<average<<endl;
cout<<"\nСамый взрослый: "<<maxAge<<endl;
cout<<"\nСамый молодой: "<<minAge<<endl;
return0;
}
The variable min we initialized value 100, so the program can work properly. If it was initialized value 0, conditionif (age < minAge) would not satisfy the ever, asage is always more 0. Thus the value of variable minAge would always remain zero.
Result:
For the job yourself, We offer you to solve a similar task. Arrange the number of visitors entering the gym and the number of hours spent by each of them in the gym. As a result, calculate and display the total amount, which customers have paid for training.
3. In stock has a certain number of boxes of apples (in this example, 15). When the car arrives for pickup, ask the user to enter, how many boxes loaded into the first car, the second and so on, until there are no more boxes of apples. Provide case, When the user enters the number of boxes more, than there is in stock.
Show code
Задача: оператор for 3
C++
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#include <iostream>
usingnamespacestd;
intmain()
{
setlocale(LC_ALL,"rus");
intboxWithApples=15;// количество ящиков на складе
intamountBoxesForSale=0;// количество отгружаемых ящиков
cout<<"Сейчас на складе "<<boxWithApples<<" ящиков с яблоками.\n\n";
for(inti=1;;i++)// счетчик i будет считать количество машин к погрузке
{
cout<<"Сколько ящиков загрузить в "<<i<<"-ю машину? ";
cin>>amountBoxesForSale;
if(amountBoxesForSale>boxWithApples)
{
cout<<"\nНа складе недостаточно товара!";
cout<<"Осталось только "<<boxWithApples<<" ящиков\n\n";
i--;// уменьшить счетчик на единицу
}
else
{
boxWithApples-=amountBoxesForSale;// перезаписываем значение
cout<<"Осталось "<<boxWithApples<<" ящиков.\n";
}
if(boxWithApples==0)// если ящиков больше нет - выйти из цикла
{
cout<<"Яблоки закончились! Давай до свидания!\n";
break;
}
}
return0;
}
"I" count in string 21 reduced per unit, so that the next iteration of the loop to show the correct serial number of the machine.
Result:
If you have questions, please contact us in the comments.
you can use any name for the counter. You can also use a variable declared before the loop. It depends on what you need to implement the code. Just do not complicate the code, inventing their own unique name for the usual standard things. For the name of the loop counter i – most that, that we should. This reduction of the index or iterator. Perhaps by indicator (counter, флаг).
int main(){ int visitors, age, older, younger, average;
cout <<visitors;
int count[visitors]; for(int i=1; i<=visitors; i++) { cout <<"Enter the age of " <<i <>count[i-1]; } older = younger = average = count[0];
for(int i=1; i<visitors; i++) { if(count[i]older) older = count[i]; average += count[i]; } cout <<"\n\nThe younger visitor is " <<younger <<" years old\n"; cout <<"The older visitor is " <<older <<" years old\n"; cout <<"The average age of visitor is: " <<average/visitors <<endl <<endl;
int main() { setlocale(LC_ALL, "rus"); int kol_vo = 0; int vozrast = 0; int maxAge = 0; int minAge = 100;
int sum = 0; cout << kol_vo; cout << "\n"; for (int i = 0; i < kol_vo; i++) { cout <> vozrast; if (vozrast > maxAge) // если оно больше, чем хранит переменная max maxAge = vozrast; // записываем в неё это число if (vozrast < minAge) minAge = vozrast; sum = sum + vozrast; } cout << "Возраст самого старшего = " << maxAge << "\n"; cout << "Возраст самого младшего = " << minAge << "\n"; cout << "Средний возраст посетителей = "<<sum/kol_vo; cin.get(); }
In the code of the first tasks of the uncertainty regarding the exit from the program. If a user wants to click “Y”, to continue, but accidentally clicks promahnotsya and any other symbol, Besides “N” – program anyway completed.
As always interesting tasks, that make think!
I agree , and I want to say thank you for a detail in the lessons :)
by the way , instead counter variable “i”, You can use a different character?
you can use any name for the counter. You can also use a variable declared before the loop. It depends on what you need to implement the code.
Just do not complicate the code, inventing their own unique name for the usual standard things. For the name of the loop counter i – most that, that we should. This reduction of the index or iterator. Perhaps by indicator (counter, флаг).
a task 2, I got such a decision:
#include#include
using namespace std;
int main(){
int visitors, age, older, younger, average;
cout <<visitors;
int count[visitors];
for(int i=1; i<=visitors; i++) {
cout <<"Enter the age of " <<i <>count[i-1];
}
older = younger = average = count[0];
for(int i=1; i<visitors; i++) {
if(count[i]older) older = count[i];
average += count[i];
}
cout <<"\n\nThe younger visitor is " <<younger <<" years old\n";
cout <<"The older visitor is " <<older <<" years old\n";
cout <<"The average age of visitor is: " <<average/visitors <<endl <<endl;
system("pause");
return 0;
}
#includeusing namespace std;
int main()
{
setlocale(LC_ALL, "rus");
int kol_vo = 0;
int vozrast = 0;
int maxAge = 0;
int minAge = 100;
int sum = 0;
cout << kol_vo;
cout << "\n";
for (int i = 0; i < kol_vo; i++)
{
cout <> vozrast;
if (vozrast > maxAge) // если оно больше, чем хранит переменная max
maxAge = vozrast; // записываем в неё это число
if (vozrast < minAge)
minAge = vozrast;
sum = sum + vozrast;
}
cout << "Возраст самого старшего = " << maxAge << "\n";
cout << "Возраст самого младшего = " << minAge << "\n";
cout << "Средний возраст посетителей = "<<sum/kol_vo;
cin.get();
}
puzzles are cool, true, I would like a little more work on cycles
In the code of the first tasks of the uncertainty regarding the exit from the program. If a user wants to click “Y”, to continue, but accidentally clicks promahnotsya and any other symbol, Besides “N” – program anyway completed.
#include#include
using namespace std;
int main()
{
setlocale(LC_ALL, "rus");
long long x = 0;
cout <> x;
if (x == 0)
break;
else
{
x = x * x;
cout << x << endl;
}
}
_getch();
return 0;
}