### Program 323:Octal to Binary Conversion in C

Octal to Binary Conversion in C
Method I:Can Accept more number of digits for conversion
```#include<stdio.h>
#include<string.h>
#include<stdlib.h>
main()
{
char *octalNum[]={"000","001","010","011","100","101","110","111"};
int i=0,number,j=1;
long long int octal,temp;
char binary[20][6];
printf("Enter Octal number\n");
scanf("%lld",&octal);
temp=octal;
while(temp!=0)
{
number=temp%10;
if(number>=0 && number<=7)
{
strcpy(binary[i],octalNum[number]);
temp/=10;
i++;
}
else
{
printf("Invalid Octal Number\n");
exit(0);
}
}
printf("Binary number for given Octal number %lld is\n",octal);
for(j=i-1;j>=0;j--)
printf("%s",binary[j]);
printf("\n");

}```

Method II:Limited number of digits Maximum only 4
```#include<stdio.h>
#include<math.h>
int ConvertFromDecimalToOther(int,int);
int ConvertFromOctaltoDecimal(int);
int main()
{
int binary,decimal,octal;
printf("Enter Octal Number\n");
scanf("%d",&octal);
decimal=ConvertFromOctaltoDecimal(octal);
binary=ConvertFromDecimalToOther(decimal,2);
printf("Binary Number for given Octal Number %d is %d\n",octal,binary);
return(0);
}
int ConvertFromDecimalToOther(int decimal,int num)
{
int temp,final=0,i,j=1;
temp=decimal;
while(temp!=0)
{
i=temp%num;
final=final+(i*j);
temp=temp/num;
j=j*10;
}
return(final);
}

int ConvertFromOctaltoDecimal(int octal)
{
int dec=0,temp,i,inc=0;
temp=octal;
while(temp!=0)
{
i=temp%10;
dec=dec+(i*pow(8,inc));
temp=temp/10;
inc++;
}
return(dec);
}
```
Explanation:

//Coming Soon...

Output:
 Method I

 Method I

 Method II