C Exercises: Find the the Authomorphic numbers between 1 to 1000

Last update on August 05 2025 12:55:51 (UTC/GMT +8 hours)

22. Automorphic Numbers Between 1 and 1000 Variants

Write a program in C to find the Authomorphic numbers between 1 and 1000.

Sample Solution:

C Code:

# include <stdio.h>
# include <stdlib.h>
# include <stdbool.h>

// Function to check if a number is an Automorphic Number
bool chkAutomor(int num1)
{
    int sqno = num1 * num1;  // Calculating the square of the number
    while (num1 > 0)  // Loop to compare digits of 'num1' and its square
    {
        if (num1 % 10 != sqno % 10)  // Checking if the last digits of 'num1' and its square are not equal
            return false;  // Returning false if the last digits are not equal
        num1 /= 10;  // Moving to the next digit in 'num1'
        sqno /= 10;  // Moving to the next digit in its square
    }
    return true;  // Returning true if all digits match
}

// Main function
int main()
{
    int i;  // Loop variable

    // Printing information about the program
    printf("\n\n Find the the Automorphic numbers between 1 to 1000 \n");
    printf(" -------------------------------------------------------\n");
    printf(" The Automorphic numbers are: ");

    for (i = 1; i <= 1000; i++)  // Loop to check for Automorphic Numbers from 1 to 1000
    {
        if (chkAutomor(i))  // Checking if 'i' is an Automorphic Number using the function
            printf("%d ", i);  // Printing 'i' if it is an Automorphic Number
    }

    printf("\n");  // Print a new line after displaying all Automorphic Numbers between 1 and 1000

    return 0;  // Returning 0 to indicate successful execution
}

Sample Output:

 The Authomorphic numbers are: 1 5 6 25 76 376 625

Visual Presentation:

C programming: Check if a number is Authomorphic or not.

Flowchart:

For more Practice: Solve these Related Problems:

Write a C program to generate automorphic numbers within a given range dynamically.
Write a C program to count automorphic numbers and display their squares alongside the original numbers.
Write a C program to list automorphic numbers with detailed digit matching information.
Write a C program to optimize the detection of automorphic numbers using pattern recognition.

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