# Python | Check if there are K consecutive 1’s in a binary number

• Last Updated : 28 Aug, 2020

Given K and a binary number, check if there exists k consecutive 1’s in the binary number.

Examples:

```Input : binary number = 101010101111
k = 4
Output : yes
Explanation: at the last 4 index there exists
4 consecutive 1's

Input : binary number = 11100000 k=5
Output : no
Explanation: There is a maximum of 3 consecutive
1's in the given binary.
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: Create a new string with k 1’s. Using if condition check if there is new in s. In python if new in s: checks if there is any existence if new in s, hence returns true if there is else it returns a false.

Below is the Python implementation of the above approach:

 `# Python program to check if there ``# is k consecutive 1's in a binary number `` ` `# function to check if there are k ``# consecutive 1's ``def` `check(s,k):``     ` `    ``# form a new string of k 1's ``    ``new ``=` `"1"``*``k ``     ` `    ``# if there is k 1's at any position ``    ``if` `new ``in` `s:``        ``print` `"yes"` `    ``else``:``        ``print` `"no"` ` ` `# driver code``s ``=` `"10101001111"``k ``=` `4` `check(s, k)`

Output:

```yes
```
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