C 프로그래밍의 루프 및 조건문 마스터링

#include <stdio.h>

int main() {
 int num = 10;

if (num > 0) {
  printf("Number is positive.\n");
 } else if (num < 0) {
  printf("Number is negative.\n");
 } else {
 printf("Number is zero.\n");
 }
 return 0;
}

#include <stdio.h>

int RevNum(int num) {
    int R = 0;

    // Reversing the number
    while (num != 0) {
        int remainder = num % 10;
        R = R * 10 + remainder;
        num /= 10;
    }    
    return R;
}
int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);
    printf("Reversed number: %d\n", RevNum(num));
    return 0;
}

#include <stdio.h>
#include <math.h>

// Function to calculate the number of digits in a number
int countDigits(int num) {
    int count = 0;
    while (num != 0) {
        num /= 10;
        ++count;
    }
    return count;
}

// Function to check if a number is an Armstrong number
int isArmstrong(int num) {
    int No, remainder, result = 0, n = 0, power;

    No = num;

    // Count number of digits
    n = countDigits(num);

    // Calculate result
    while (No != 0) {
        remainder = No % 10;

        // Power of remainder with respect to the number of digits
        power = round(pow(remainder, n));
        result += power;
        No /= 10;
    }

    // Check if num is an Armstrong number
    if (result == num)
        return 1; // Armstrong number
    else
        return 0; // Not an Armstrong number
}


int main() {
    int num;

    printf("Enter a number: ");
    scanf("%d", &num);

    if (isArmstrong(num))
        printf("%d is an Armstrong number  =  ", num);
    else
        printf("%d is not an Armstrong number  =  ", num);

    return 0;
}

#include <stdio.h>
// Function to check if a number is palindrome or not
int P(int num) {
    int i = 0, no = num;
        // Reversing the number
    while (num != 0) {
        int remainder = num % 10;
        i = i * 10 + remainder;
        num /= 10;
    }    
    // Checking if the reversed number is equal to the original number
    if (no == i)
        return 1; // Palindrome no
    else
        return 0; // Not a palindrome
   end if
}
int main() 
{
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);
    if (P(num))
        printf("%d palindrome no.\n", num);
    else
        printf("%d is not a palindrome no .\n", num);
 end if
    return 0;
}