BETA

Difficulty Level:

Easy

Total Submissions: 135 Accuracy:

8.15%

Count binary strings
     

Given two integers n and k, count the number of binary strings of length n with k as number of times adjacent 1’s appear.

Input:
The first line of input contains an integer T denoting the number of test cases. Then T test cases follow. The first line of each test case contains the two integers N and K.

Output:
Print the answer for each testcase in a new line. Since the answer can be quiet large output the answer modulo 109+7.

Constraints:
1<=T <=100
1<= N, K <=1000

Example:
Input:
1
5 2

Output:
6

** For More Input/Output Examples Use 'Expected Output' option **

Contributor: Sujnesh Mishra

Set Default Code

					   
It is recommended to 'Compile & Test' your code before clicking 'Submit'!

Compilation/Execution Result:

Need help with your code? Please use ide.geeksforgeeks.org, generate link and share the link here.