Function to check if the number is even or odd

Sure! Here's a Python function to check if a number is even or odd:

def is_even(num):
    if num % 2 == 0:
        return True
    else:
        return False

You can call this function with any integer value as an argument, and it will return `True` if the number is even and `False` if it's odd. For example:

>>> is_even(4)
True
>>> is_even(7)
False

相关问题

Write a C function named isPrime that checks whether a given number is a prime or not. Include the fuction isPrime in a working program to verify Goldbach's Conjecture: Every even number greater than 4 can be written as the sum of two odd prime numbers. Make sure the function isPrime is called from the main method, and correctly returns a value to the main method.

Sure, here is a C program that includes the `isPrime` function to verify Goldbach's Conjecture:

#include <stdio.h>

int isPrime(int num);

int main() {
    int num, i, j;
    
    printf("Enter an even number greater than 4: ");
    scanf("%d", &num);
    
    if (num <= 4 || num % 2 != 0) {
        printf("Invalid input!\n");
        return 0;
    }
    
    for (i = 3; i <= num / 2; i += 2) {
        if (isPrime(i) && isPrime(num - i)) {
            printf("%d = %d + %d\n", num, i, num - i);
        }
    }
    
    return 0;
}

int isPrime(int num) {
    int i;
    
    if (num < 2) {
        return 0;
    }
    
    for (i = 2; i <= num / 2; i++) {
        if (num % i == 0) {
            return 0;
        }
    }
    
    return 1;
}

The `isPrime` function takes an integer as input and returns 1 if the number is prime, and 0 otherwise. The `main` function prompts the user to enter an even number greater than 4, and then checks whether the input is valid. If the input is valid, the program uses a for loop to check all odd prime numbers less than or equal to half of the input number. For each odd prime number `i`, the program checks whether the difference between the input number and `i` is also a prime number. If both numbers are prime, the program prints out the input number as the sum of `i` and the difference between the input number and `i`. If no such pairs of prime numbers are found, the program prints nothing. The `isPrime` function is called from the `main` function to check whether each number is prime.

编写一个名为collatz()的函数，它有一个名为number的参数。如果参数是偶数，那么collatz()就输出number//2,并返回该值。如果number是奇数，collatz就输出并返回3*number+1。

当然可以，这是一个简单的函数设计，使用了所谓的Collatz猜想，也称为3x+1序列。你可以按照以下方式编写这个Python函数：

def collatz(number):
    """
    This function takes an integer 'number' as input and follows the Collatz sequence rules.
    
    If the number is even, it divides by 2 (number // 2).
    If the number is odd, it multiplies by 3 and adds 1 (3 * number + 1).

    :param number: An integer to start the Collatz sequence.
    :return: The next number in the Collatz sequence.
    """
    if number % 2 == 0:  # Check if number is even
        return number // 2
    else:
        return 3 * number + 1

# Test the function with some values
print(collatz(5))  # Output: 16
print(collatz(10))  # Output: 5

在这个函数中，我们首先检查输入数字是否是偶数，如果是，则除以2；如果不是，乘以3加1。然后返回新的结果，这个过程一直持续到数字变为1为止，因为所有奇数都会按照这个规律最终变成1。