C Exercises: Convert Octal number to a Decimal number

C For Loop: Exercise-51 with Solution

Write a program in C to convert a Octal number to a Decimal number without using an array, function and while loop.

Pictorial Presentation:

Sample Solution:

C Code:

#include <stdio.h>

void main()
{       int n1, n5,p=1,k,ch=1;
	int dec=0,i=1,j,d;

     printf("\n\nConvert Octal to Decimal:\n ");
     printf("-------------------------\n");

	printf("Input an octal number (using digit 0 - 7) :");
	scanf("%d",&n1);
	n5=n1;

    for(;n1>0;n1=n1/10)
    {
       k=n1 % 10;
       if(k>=8) 
       { 
        ch=0;
       }
     }

  switch(ch)
    {
    case 0 :
        printf("\nThe number is not an octal number. \n\n");
        break;
    case 1:
        n1=n5;
	for (j=n1;j>0;j=j/10)
	{  
          d = j % 10;
            if(i==1)
                  p=p*1;
            else
                 p=p*8;

	   dec=dec+(d*p);
	   i++;
	}
        printf("\nThe Octal Number : %d\nThe equivalent Decimal  Number : %d \n\n",n5,dec);
        break;
    }
}

Sample Output:

Convert Octal to Decimal:                                                                                     
 -------------------------                                                                                    
Input an octal number (using digit 0 - 7) :745                                                                
                                                                                                              
The Octal Number : 745                                                                                        
The equivalent Decimal  Number : 485  

Flowchart:

C Programming Code Editor:

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