PROBLEM OF THE DAY : 03/06/2024 | Trail of ones

Welcome to the daily solving of our PROBLEM OF THE DAY with Nitin Kaplas. We will discuss the entire problem step-by-step and work towards developing an optimized solution. This will not only help you brush up on your concepts of Bits Manipulation but also build up problem-solving skills.

Given a number n, find the number of binary strings of length n that contain consecutive 1's in them. Since the number can be very large, return the answer after modulo with 1e9+7.

Example 1:

Input: n = 2
Output: 1
Explanation: There are 4 strings of length 2, the strings are 00, 01, 10, and 11. Only the string 11 has consecutive 1's.

Give the problem a try before going through the video. All the best!!!
Problem Link: https://practice.geeksforgeeks.org/problems/trail-of-ones3242/1