Decimal to Binary

A simple C++ program to convert floating point numbers to binary. Works by using modf to separate the fractional and integer part of the number. Performs integer to binary calculation on the integer part and then it performs fractional to binary calculation on the fractional part. Source Link.

Decimal to Binary

#include <iostream>

#include <string.h>

#include <math.h>

using namespace std;

// limit to how long the binary string is.

#define MAX_BIN 1077

/* Mao ni ang function para sa integer na part */

void f2binI(double fInt, char* strBinary) {

int iCount = 0;

int i;

char strBuffer[MAX_BIN];

do {

strBuffer[iCount++] = '0' + (int)fmod(fInt,2);

fInt = floor(fInt/2);

} while (fInt > 0);

/* Reverse the binary string */

for (i=0; i<iCount; i++)

strBinary[i] = strBuffer[iCount-i-1];

strBinary[iCount] = 0; //Null terminator

}

/* Mao ni ang function para sa fractional na part */

void f2binF(double fFrac, char* strBinary) {

int iCount = 0;

double fInt;

while (fFrac > 0)

{

fFrac*=2;

fFrac = modf(fFrac,&fInt);

strBinary[iCount++] = '0' + (int)fInt;

}

strBinary[iCount] = 0; //Null terminator

}

/* automatic na ni xa mo decide gamit modf para 

i convert ang integer ug fractional na part. */

void f2bin(double fp, char* strBinary) {

double fInt, fFrac;

/* Separate integer and fractional parts */

fFrac = modf(fp,&fInt);

/* Convert integer part, if any */

if (fInt != 0)

f2binI(fInt,strBinary);

else

strcpy(strBinary,"0");

strcat(strBinary,"."); // Radix point

/* Convert fractional part, if any */

if (fFrac != 0)

f2binF(fFrac,strBinary+strlen(strBinary)); //Append

else

strcpy(strBinary+strlen(strBinary),"0");

}

int main()

{

double fInput;

cout << "Enter a floating point number: ";

cin >> fInput;

char strBinary[MAX_BIN];

f2bin(fInput,strBinary);

cout << "Float " << fInput << " = " << strBinary;

return 0;

}

Integer to Binary in C

Source: http://j.mp/eBmv83

Decimal to Binary in C

// Convert a decimal integer do a binary string

// added a test printf() you can remove later

// Turbo C modified for Pelles C     vegaseat    19nov2004

#include <stdio.h>

void dec2bin(long decimal, char *binary);

int main()

{

  long decimal;

  char binary[80];

  printf("\n\n Enter an integer value : ");

  scanf("%ld",&decimal);

  dec2bin(decimal,binary);

  printf("\n The binary value of %ld is %s \n",decimal,binary);

  getchar();  // trap enter 

  getchar();  // wait

  return 0;

}

//

// accepts a decimal integer and returns a binary coded string

//

void dec2bin(long decimal, char *binary)

{

  int  k = 0, n = 0;

  int  neg_flag = 0;

  int  remain;

  int  old_decimal;  // for test

  char temp[80];

  // take care of negative input

  if (decimal < 0)

  {      

    decimal = -decimal;

    neg_flag = 1;

  }

  do 

  {

    old_decimal = decimal;   // for test

    remain    = decimal % 2;

    // whittle down the decimal number

    decimal   = decimal / 2;

    // this is a test to show the action

    printf("%d/2 = %d  remainder = %d\n", old_decimal, decimal, remain);

    // converts digit 0 or 1 to character '0' or '1'

    temp[k++] = remain + '0';

  } while (decimal > 0);

  if (neg_flag)

    temp[k++] = '-';       // add - sign

  else

    temp[k++] = ' ';       // space

  // reverse the spelling

  while (k >= 0)

    binary[n++] = temp[--k];

  binary[n-1] = 0;         // end with NULL

}

Decimal to Binary in C++

Version 1

This version does not have functions.

Source: http://j.mp/idz1A5

Decimal to Binary in C++

#include<iostream>

using namespace std;

int bin(int num);

int main()

{

    cout<<"Enter a <strong class="highlight">binary</strong> number ";

    int num;

    cin>>num;

    cout<<endl<<endl;

    bin(num);

    cout<<endl<<endl;

    system("PAUSE");

    return 0;

}

int bin(int num)

{

    int a[25];

    int i;

    i=0;

    int r;

    int d;

    int b;

    int j;

    j= 0; 

    cout<<"<strong class="highlight">Binary</strong> is : ";      

    while(num>0)

    {

          r=num%2;

          a[j]=r;

          d=num/2;

          b=num;

          num=d;

          j++;

    }    

    while(j>=0)

    {

              cout<<a[j];

              j--;

    }

}

Version 2

This version uses malloc to resize array pointers for functions.

Source: http://j.mp/ieA825

Decimal to Binary in C++ Using Functions and Pointers

#include<iostream>

#include<stdlib.h>

using namespace std;

class d2b

{

public:

int dec2bin(int *p)

{

int a,b,c=1,d=0;

while (*p!=0)

{

a = *p%2;

b = a * c;

d = d + b;

*p = *p/2;

c = c * 10;

}

return d;

}

};

int main()

{

d2b db;

int *n,x,y;

n = (int*)malloc(sizeof(int));

cout<<"Enter the decimal number: ";

cin>>*n;

y = *n;

x = db.dec2bin(n);

cout<<"The binary conversion of "<<y<<" is "<<x<<endl;

return 0;

}

Version 3

This version can convert floats and doubles by dividing the number to its fractional and integer parts. Another algorithm is used to convert the fractional part in to binary.

Source: http://j.mp/fcIrnE

Float to Binary in C++

#include <iostream>

#include <string.h>

#include <math.h>

using namespace std;

// limit to how long the binary string is.

#define MAX_BIN 1077

/* Mao ni ang function para sa integer na part */

void f2binI(double fInt, char* strBinary) {

int iCount = 0;

int i;

char strBuffer[MAX_BIN];

do {

strBuffer[iCount++] = '0' + (int)fmod(fInt,2);

fInt = floor(fInt/2);

} while (fInt > 0);

/* Reverse the binary string */

for (i=0; i<iCount; i++)

strBinary[i] = strBuffer[iCount-i-1];

strBinary[iCount] = 0; //Null terminator

}

/* Mao ni ang function para sa fractional na part */

void f2binF(double fFrac, char* strBinary) {

int iCount = 0;

double fInt;

while (fFrac > 0)

{

fFrac*=2;

fFrac = modf(fFrac,&fInt);

strBinary[iCount++] = '0' + (int)fInt;

}

strBinary[iCount] = 0; //Null terminator

}

/* automatic na ni xa mo decide gamit modf para 

i convert ang integer ug fractional na part. */

void f2bin(double fp, char* strBinary) {

double fInt, fFrac;

/* Separate integer and fractional parts */

fFrac = modf(fp,&fInt);

/* Convert integer part, if any */

if (fInt != 0)

f2binI(fInt,strBinary);

else

strcpy(strBinary,"0");

strcat(strBinary,"."); // Radix point

/* Convert fractional part, if any */

if (fFrac != 0)

f2binF(fFrac,strBinary+strlen(strBinary)); //Append

else

strcpy(strBinary+strlen(strBinary),"0");

}

int main()

{

double fInput;

cout << "Enter a floating point number: ";

cin >> fInput;

char strBinary[MAX_BIN];

f2bin(fInput,strBinary);

cout << "Float " << fInput << " = " << strBinary;

return 0;

}