C program to convert decimal fraction to binary fraction

Consider the examples given below to understand how to convert a decimal fraction to binary fraction in C programming language.

Example 1 − Conversions of 25 to binary.

Step 1 − 25 / 2 Rem : 1 , Quo : 12

Step 2 − 12 / 2 Rem : 0 , Quo : 6

Step 3 − 6 / 2 Rem : 0 , Quo: 3

Step 4 − 3 / 2 Rem : 1 , Quo: 1

Step 5 − 1 / 2 Rem : 1 , Quo: 0

So equivalent binary number is: 11001

Example 2 − Conversions of 0.7 to binary.

Step 1 − 0.7 * 2 = 1.4, Int part = 1

Step 2 − 0.4 * 2 = 0.8, Int part = 0

Step 3 − 0.8 * 2 = 1.6, Int part = 1

Step 4 − 0.6 * 2 = 1.2, Int part = 1

Step 5 − 0.2 * 2 = 0.4, Int part = 0

Step 6 − 0.4 * 2 = 0.8, Int part = 0

So equivalent binary number is: 0.101100

Step 3 − Finally, the binary value of decimal number 25.7 is as follows −

11001 + 0.101100 = 1101.101100

Example

Following is the C program to convert a decimal fraction to binary fraction −

 Live Demo

#include<stdio.h>
int main(){
   long double fraDecimal,fraBinary,bFractional = 0.0,dFractional,fraFactor=0.1;
   long int dIntegral,bIntegral=0;
   long int intFactor=1,remainder,temp,i;
   printf("Enter any fractional decimal number: ");
   scanf("%Lf",&fraDecimal);
   dIntegral = fraDecimal;
   dFractional = fraDecimal - dIntegral;
   while(dIntegral!=0){
      remainder=dIntegral%2;
      bIntegral=bIntegral+remainder*intFactor;
      dIntegral=dIntegral/2;
      intFactor=intFactor*10;
   }
   for(i=1;i<=6;i++){
      dFractional = dFractional * 2;
      temp = dFractional;
      bFractional = bFractional + fraFactor* temp;
      if(temp ==1)
         dFractional = dFractional - temp;
      fraFactor=fraFactor/10;
   }
   fraBinary = bIntegral + bFractional;
   printf("Equivalent binary value: %lf",fraBinary);
   return 0;
}

Output

When the above program is executed, it produces the following result −

Enter any fractional decimal number: 5.7
Equivalent binary value: 101.101100