Илэрхийлэл
Энэ бодлогыг бодохын тулд бутархай тоон төрөл ашиглаж мэддэг байх хэрэгтэй. C++ хэлэнд double болон float гэх 2 бутархай тоон төрөл байна.
C++ хэлний хувьсагчийн төрлүүд.
| Төрөл | bytes | Доод хэмжээ | Дээд хэмжээ |
|---|---|---|---|
| Float | 4bytes | 1.8E-38 | 3.4E+38 |
| Double | 8bytes | 2.2E-308 | 1.8E+308 |
| Long Double | 8 | 2.2E-308 | 1.8E+308 |
| Character | 1 | -128 | 127 |
| Unsigned Char | 1 | 0 | 255 |
| Signed Char | 1 | -128 | 127 |
| Integer | 4 | -2,147,483,648 | 2,147,483,647 |
| Signed Int | 4 | 0 | 4,294,967,295 |
| Unsigned Int | 4 | -2,147,483,648 | 2,147,483,647 |
| Short Int | 2 | -32,768 | 32,767 |
| Signed short Int | 2 | 0 | 65,535 |
| Unsigned Short Int | 2 | -32,768 | 32,767 |
| Long Int | 4 | -2,147,483,648 | 2,147,483,647 |
| Signed Long Int | 8 | 0 | 4,294,967,295 |
| Unsigned Long Int | 8 | -2,147,483,648 | 2,147,483,647 |
| Bool | 1 | True/False | True/False |
| Wchar_t | 2 or 4 | 0 | 65,535 |
| Long Long Int | 8 | -9,223,372,036,854,775,807 | 9,223,372,036,854,775,807 |
| Unsigned Long Long Int | 8 | 0 | 18,446,744,073,709,551,615 |
Double болон float төрлийг ашиглах.
#include <iostream>
#include <iomanip>
#include <cstdio>
using namespace std;
int main(){
double a = 2.0 / 3.0;
// Таслалаас хойш 3 оронгийн нарийвчлалтай хэвлэх.
cout << "cout: " << setprecision(3) << a << "\n";
printf("printf: %.3lf\n", a);
cout << "a = ";
cin >> a;
cout << "cout: a = " << a << endl;
printf("a = ");
scanf("%lf", &a);
printf("printf: a = %lf\n", a);
}
Гаралт
Бодлогын бодолт
#include <iostream>
#include <iomanip>
#include <cstdio>
using namespace std;
int main() {
double x, y;
scanf("%lf", &x);
y = ((x * x * x) + 5.0 * x * x - 3.0 * x + 7.0) / (x + 4.0);
printf("%.3lf", y);
return 0;
}