# C++ Program for Decimal to binary conversion

## Program for Decimal to binary conversion

Here, we will discuss decimal to binary conversion in C++.The concept of conversion is very simple.A decimal number can be converted to a binary number by using the repeated division-by-2 method i.e repeatedly divide the decimal number by 2 until no further divisions can be done and the remainder of each division will give us the binary number of the decimal.

Example:9

1) 9/2, Remainder = 1, Quotient = 4,

2) 4/2, Remainder = 0, Quotient = 2

3) 2/2, Remainder = 0, Quotient = 1,

4) 1/2, Remainder = 1, Quotient = 0

9 in decimal = 1001 in binary

## Algorithm:-

1. User gives an input(decimal number).
2. The input is stored in an int type variable say decimal.
3. A function convert is called with decimal as a parameter.
1. A loop is started
1. The number is divided by 2 and the remainder is stored.

rem = n%2;

2. The binary number is constructed using the remainder.

binary += rem*i;

2. The loop will run until the number is not equal to 0.

while (n!=0)

4. The output is printed.

## C++ Code:

`//C++ Program//Decimal to binary conversion#include <bits/stdc++.h>using namespace std;//function to convert decimal to binarylong convert(int n){  long binary = 0; int i = 1; //converting decimal to binary while(n!=0){   int rem = n%2;   n /= 2;   binary += rem*i;   i *= 10; } return binary;}//main programint main(){ int decimal; long binary;  cout<<"Enter a decimal number: "; //user input cin>>decimal;  //calling function binary = convert(decimal); cout <<decimal<<" in decimal = "<<binary<<" in binary" <<endl;  return 0;}`
`OutputEnter a decimal number: 109109 in decimal = 1101101 in binary`