C Program to Find the Sum of Even and Odd Numbers

# C Program to Find the Sum of Even and Odd Numbers

In this C programming tutorial, we will write a program to find the sum of even and odd numbers from 1 to n, where n is a positive integer entered by the user. This program demonstrates the use of loops, conditional statements, and arithmetic operations in C programming.

Problem Statement:

Write a C program to find the sum of even and odd numbers from 1 to n, where n is a positive integer entered by the user.

Solution:

To solve this problem, we will use a `for` loop to iterate over the numbers from 1 to n. Inside the loop, we will use an `if` statement to check whether the current number is even or odd, and we will update the sum of even and odd numbers accordingly. Here’s the code for our solution:

```#include <stdio.h>

int main() {
int n, i, even_sum = 0, odd_sum = 0;

printf("Enter a positive integer: ");
scanf("%d", &n);

for(i = 1; i <= n; i++) {
if(i % 2 == 0) {
even_sum += i;
}
else {
odd_sum += i;
}
}

printf("Sum of even numbers from 1 to %d is %d\n", n, even_sum);
printf("Sum of odd numbers from 1 to %d is %d\n", n, odd_sum);

return 0;
}
```

Output

1. The `stdio.h` header file is included for standard input/output functions.
2. The `main()` function is declared as the entry point of the program.
3. The `start`, `end`, `even_sum`, and `odd_sum` variables are declared. `even_sum` and `odd_sum` are initialized to zero.
4. The user is prompted to enter the starting number using `printf()` function.
5. The user input is read and stored in the `start` variable using `scanf()` function.
6. The user is prompted to enter the ending number using `printf()` function.
7. The user input is read and stored in the `end` variable using `scanf()` function.
8. A `for` loop is used to iterate through the numbers in the range from `start` to `end`.
9. An `if-else` statement is used to determine whether each number is even or odd.
10. If the number is even (i.e., the remainder when dividing by 2 is 0), the `even_sum` variable is updated to include the number.
11. If the number is odd (i.e., the remainder when dividing by 2 is 1), the `odd_sum` variable is updated to include the number.
12. Once the loop is complete, two `printf()` statements are called to display the sum of even and odd numbers in the given range.
13. The `main()` function returns 0, which indicates that the program has executed successfully.

Explanation:

The program begins by including the `stdio.h` header file, which provides access to standard input/output functions. The `main()` function is then declared as the entry point of the program, and the `start`, `end`, `even_sum`, and `odd_sum` variables are declared.

Next, the user is prompted to enter the starting number and the ending number using the `printf()` function. The `scanf()` function is then used to read the user input and store it in the `start`