# C++ program to divide a number by 3 without using *, / , +, -, % operators

For a given positive number we need to divide a number by 3 without using any of these *, /, +, – % operators

Examples:

Input : 48 Output : 16 Input : 16 Output : 5

**Algorithm**

- Take a number num, sum = 0
- while(num>3), shift the number left by 2 bits and sum = add(num >> 2, sum). Create a function add(x, y) for adding two number by bitwise opreator
- Take x, y
- run a do while loop till a is not zero
- a = x & y, b = x ^ y;, y = b;
- after terminating loop return value of b which gives sum of x and y

- Take bitwise AND of num with 3

for new num = add( num >> 2, num & 3) - After terminating while loop print the value of sum which give final result .

For example if your number is 10 then convert to binary 10 => 00001010

If 10 > 3 then shift the binary number 2 bits, Now num will be 00000010 i.e, 2

Now sum will be 2

num = (shift the number by 2 bits) + (number BITWISE AND 3)

num = 2+2

Now the number will be 4 then, 4 > 3 => true so loop will be repeated

4 => 00000100 then shift the binary number 2 bits

Now sum = 2 + 1 ie, sum = 3 (this value is returned)

num = (shift the number(00000100) by 2 bits) + (number BITWISE AND 3)

num = 1 + 0

ie remainder = 1

`// C++ program for divided a number by ` `// 3 without using operator ` `#include <bits/stdc++.h> ` `using` `namespace` `std; ` ` ` `// A function to add 2 numbers without using + ` `int` `add(` `int` `x, ` `int` `y) ` `{ ` ` ` `int` `a, b; ` ` ` `do` `{ ` ` ` `a = x & y; ` ` ` `b = x ^ y; ` ` ` `x = a << 1; ` ` ` `y = b; ` ` ` `} ` `while` `(a); ` ` ` ` ` `return` `b; ` `} ` ` ` `// Function to divide by 3 ` `int` `divideby3(` `int` `num) ` `{ ` ` ` `int` `sum = 0; ` ` ` ` ` `while` `(num > 3) { ` ` ` `sum = add(num >> 2, sum); ` ` ` `num = add(num >> 2, num & 3); ` ` ` `} ` ` ` ` ` `if` `(num == 3) ` ` ` `sum = add(sum, 1); ` ` ` ` ` `return` `sum; ` `} ` ` ` `// Driver program ` `int` `main(` `void` `) ` `{ ` ` ` `int` `num = 48; ` ` ` `cout << ` `"The number divided by 3 is "` `; ` ` ` `cout << divideby3(num); ` ` ` ` ` `return` `0; ` `} ` |

*chevron_right*

*filter_none*

**Output:**

The number divided by 3 is 16

This article is contributed by **DANISH_RAZA**. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

## Recommended Posts:

- Find the number of ways to divide number into four parts such that a = c and b = d
- Count number of ways to divide a number in 4 parts
- Find count of digits in a number that divide the number
- Sum and Product of digits in a number that divide the number
- Divide a number into two parts
- Divide a big number into two parts that differ by k
- Count digits in given number N which divide N
- Check if all digits of a number divide it
- Divide large number represented as string
- Divide a number into two parts such that sum of digits is maximum
- Divide number into two parts divisible by given numbers
- Count number of ways to divide an array into two halves with same sum
- Minimum positive integer to divide a number such that the result is an odd
- Check if a number is multiple of 5 without using / and % operators
- Maximum number of region in which N non-parallel lines can divide a plane