C Exercises: Convert binary number to octal

C For Loop: Exercise-53 with Solution

Write a C program to convert a binary number to octal.

Visual Presentation:

Sample Solution:

C Code:

#include 
#include 
int main() {
    // Declare variables
    int n1, n, p = 1;
    int dec = 0, i = 0, d;
    int ocno = 0, dn;
    // Print output headers
    printf("\n\nConvert Binary to Octal:\n ");
    printf("-------------------------\n");
    // Get binary input
    printf("Input a binary number: ");
    scanf("%d", &n);
    // Store input number
    n1 = n;
    // Convert binary to decimal
    // Loop through each binary digit
    while (n > 0) {
        // Get current digit
        d = n % 10;
        // Add digit * power of 2 to result
        dec += d * pow(2, i);
        // Increment power
        i++;
        // Divide binary number
        n = n / 10;
    }
    // Convert decimal to octal
    dn = dec; // Store decimal number
    i = 1;    // Reset power
    // Repeatedly divide decimal by 8
    while (dec > 0) {
        // Get remainder and add to result
        ocno += (dec % 8) * i;
        // Update power of 8
        i = i * 10;
        // Divide decimal number
        dec = dec / 8;
    }
    // Print binary and octal result
    printf("\nThe Binary Number: %d\nThe equivalent Octal Number: %d\n\n", n1, ocno);
    return 0;
}

Sample Output:

Convert Binary to Octal:                                                                                      
 -------------------------                                                                                    
Input a binary number :1001                                                                                   
                                                                                                              
The Binary Number : 1001                                                                                      
The equivalent Octal  Number : 11 

Explanation

Here's a brief explanation.

• Header and Declarations:
• Includes the necessary header files ('stdio.h' for input/output and 'math.h' for mathematical functions).
• Declare variables 'n1' (input binary number), 'n' (temporary variable for input processing), 'p' (power of 2 multiplier), 'dec' (resulting decimal number), 'd' (temporary variable for digit extraction), 'ocno' (resulting octal number), 'dn' (backup of decimal number), i (loop variable).
• User input:
• Asks the user to input a binary number.
• Reads the input and stores it in the variable 'n'.
• Binary to Decimal Conversion (using a for loop):
• Iterates through each binary number digit using a "for" loop.
• Extracts the current digit and calculates its contribution to the decimal number using the 'pow' function.
• Accumulates the result in the variable 'dec'.
• Convert Decimal to Octal (using a for loop):
• Initialize 'ocno' to 0 and i to 1 for the octal conversion.
• Repeatedly divides the decimal number ('dec') by 8 using a "for" loop.
• Calculates the remainder and adds it to the octal result ('ocno').
• Update the power of 8 (i).
• Continue until the decimal number becomes 0.
• Result Display:
• Prints the input binary number and its equivalent octal number.
• Return Statement:
• Returns 0 to indicate successful execution.

Flowchart :

C Programming Code Editor:

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