Skip to main content

Featured

C Program to Solve Two Sum Using Brute Force (With Algorithm & Output)

 Introduction The Two Sum problem is a popular coding interview question where we must find two indices of an array whose values add up to a given target. This program demonstrates a simple brute-force solution in C using nested loops and dynamic memory allocation. Problem Statement Given an integer array and a target value, return the indices of the two numbers such that they add up to the target. Each input has exactly one solution, and the same element cannot be used twice. The result should return the indices, not the values. If no solution exists, return NULL.  Algorithm / Logic Explanation Start the program. Traverse the array using a loop from index 0 to numsSize - 1 . Inside this loop, use another loop starting from i + 1 to numsSize - 1 . For every pair (i, j) , check if nums[i] + nums[j] == target . If condition becomes true: Allocate memory for 2 integers using malloc() . Store indices i and j . Set returnSize = 2 . Return the result poi...
Post a Comment
Read more
Labels

C Program: Prime Number Check

C Program: Prime Number Check

🔷 C Program: Prime Number Check

#include<stdio.h>
int main( )
{
    int num, count = 0;
    printf("Enter the number:\n");
    scanf("%d", &num);

    if(num <= 1)
    {
        printf("%d is not a prime number:\n", num);
    }
    else
    {
        for(int i = 2; i <= num / 2; i++)
        {
            if(num % i == 0)
            {
                count++;
                break;
            }
        }

        if(count == 0)
        {
            printf("%d is a prime number:\n", num);
        }
        else
        {
            printf("%d is not a prime number:\n", num);
        }
    }
}

📘 Explanation:

This C program checks if a number is prime or not.

👉 A **prime number** is a number greater than 1 that is divisible only by 1 and itself.

🔸 First, the user enters a number.
🔸 If the number is less than or equal to 1, it's not prime.
🔸 If the number is greater than 1, the program checks if it has any divisors (from 2 to num/2).
🔸 If any divisor is found, `count` is incremented, and the loop breaks early for efficiency.
🔸 Finally, if no divisors are found (`count == 0`), it's a prime number.

🔍 Sample Output:

Enter the number:
7
7 is a prime number:

Enter the number:
10
10 is not a prime number:

Enter the number:
1
1 is not a prime number:

🏷️ Keywords:

C program to check prime number, prime number logic in C, beginner C programs, isPrime function, modulus operator in C, number theory in C

Labels:

Comments

Post a Comment

Popular Posts

🌙