# C program to calculate the sum of odd and even numbers

### C program to calculate the sum of odd and even numbers

#### Problem Description

This C program calculates the sum of odd and even numbers separately from 1 to n (value of n is entered by the user). The for loop starts with 1 and continue up to the number entered by the user. To check whether the number in the current iteration is odd or even, the modulus operator is used.

##### C program to calculate the sum of odd and even numbers - Source code

/*C program to find the sum of odd and even numbers from 1 to N */ #include <stdio.h> int main() { int i, n; int sum_odd = 0, sum_even = 0; printf("Enter the number up to which you want to calculate sum\n"); scanf("%d", &n); for (i = 1; i <= n; i++) { // to check whether number is odd or even if (i % 2 == 0) sum_even = sum_even + i; else sum_odd = sum_odd + i; } printf("Sum of all even numbers = %d\n", sum_even); printf("Sum of all odd numbers = %d\n", sum_odd); }

#### Program Output

Case 1: Enter the number up to which you want to calculate sum 100 Sum of all even numbers = 2550 Sum of all odd numbers = 2500 Case 2: Enter the number up to which you want to calculate sum 25 Sum of all even numbers = 156 Sum of all odd numbers = 169

#### Program Explanation

1. Two integer variables i and n are declared. Two integer variables sum_odd and sum_even are declared and initialized to 0. 2. For loop starts the first iteration with 1 and continue up to the number entered by the user (n). 3. To check whether the number in the current iteration is even or odd, modulus operator (%) is used. This operator divides the number by 2 and returns the remainder. If reminder returned is 0, the number is even otherwise it is odd. 4. The value of sum_even and sum_odd operators is updated inside the loop and printed when the loop ends.