8876. Integer

One real number n is given. Check if it is an integer.

Input. One real number n.

Output. Print “Ok” if n is an integer, and “No” otherwise.

Sample input 1	Sample output 1
7.000	Ok
Sample input 2	Sample output 2
-21.121	No

SOLUTION

mathematics

Algorithm analysis

The number n is an integer if its integer part matches the number itself. That is, if the equality floor(n) = n holds.

Algorithm implementation

Read the real number n.

scanf("%lf", &n);

Сompare the number n with its integer part. If these values are equal, then n is an integer.

if (floor(n) == n) puts("Ok");

else puts("No");

Java implementation

import java.util.*;

class Main

{

public static void main(String[] args)

{

Scanner con = new Scanner(System.in);

double n = con.nextDouble();

if (Math.floor(n) == n)

System.out.println("Ok");

else

System.out.println("No");

con.close();

}

}

Python implementation

import math

Read the real number n.

n = float(input())

Сompare the number n with its integer part. If these values are equal, then n is an integer.

if math.floor(n) == n: print("Ok")

else: print("No")

Python implementation – is_integer

Read the real number n.

n = float(input())

The method is_integer() checks whether the given floating-point number represents an integer value (its fractional part is zero).

if n.is_integer(): print("Ok")

else: print("No")