- Related Questions & Answers
- Maximum length of segments of 0’s and 1’s in C++
- Count the number of 1’s and 0’s in a binary array using STL in C++
- 1’s and 2’s complement of a Binary Number?
- Maximum sub-matrix area having count of 1’s one more than count of 0’s in C++
- Find the number of integers from 1 to n which contains digits 0’s and 1’s only in C++
- Binary representation of next greater number with same number of 1’s and 0’s in C Program?
- C/C++ Program to Count number of binary strings without consecutive 1’s?
- Program to Count number of binary strings without consecutive 1’s in C/C++?
- Maximum 0’s between two immediate 1’s in binary representation in C++
- Segregate 0’s and 1’s in an array list using Python?
- Count number of binary strings without consecutive 1's in C
- Count 1’s in a sorted binary array in C++
- Python Program to Count number of binary strings without consecutive 1’
- Find a Symmetric matrix of order N that contain integers from 0 to N-1 and main diagonal should contain only 0’s in C++
- Maximum length of consecutive 1’s in a binary string in Python using Map function

- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who

We are given a number let’s say, num and the task is to calculate the count of binary strings that can be formed through the given number num containing only o’s and 1’s.

Binary Number System is one the type of Number Representation techniques. It is most popular and used in digital systems. Binary system is used for representing binary quantities which can be represented by any device that has only two operating states or possible conditions. For example, a switch has only two states: open or close.

In the Binary System, there are only two symbols or possible digit values, i.e., 0 and 1. Represented by any device that only has 2 operating states or possible conditions. Binary strings are those strings that contains binary values i.e. either 0’s or 1’s

Input− num = 3Output− count is 8

**Explanation** − binary combinations that can be formed of length 3 are:000, 111, 001,101, 100, 110, 011, 010 since they are total 8 in numbers therefore the count is 8.

Input− num = 2Output− count is 4

**Explanation** − binary combinations that can be formed of length 2 are:00, 11, 01,10 since they are total 4 in numbers therefore the count is 4.

Input a number of type long long as the number can be any digit long

Calculate the mod value as (long long)(le9 + 7)

Create a function to calculate the count

Declare a temporary variable that will store the count and another variable temp and initialises it with 2.

Set num as temp = temp % mod

Start loop while num > 0

Check IF num & 1 then set count as (count * temp)% mod

Set num = num >> 1

Set temp = (temp * temp) % mod

Return count

Print the result.

#include <iostream> using namespace std; #define ll long long #define mod (ll)(1e9 + 7) // An iterative function to find (x^y)%p in O(log y) ll power(ll x, ll y, ll p){ ll result = 1; x = x % p; // Update x if it is more than or // equal to p while (y > 0){ // If y is odd, multiply x with result if (y & 1){ result = (result * x) % p; } // y must be even now y = y >> 1; // y = y/2 x = (x * x) % p; } return result; } // Function to count the number of binary strings ll countbstring(ll num){ int count = power(2, num, mod); return count; } int main(){ ll num = 3; cout <<"count is: "<<countbstring(num); return 0; }

If we run the above code we will get the following output −

count is: 8

Advertisements