# 1461. Check If a String Contains All Binary Codes of Size K

<https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k>

## Description

Given a binary string `s` and an integer `k`.

Return `true` *if every binary code of length* `k` *is a substring of* `s`. Otherwise, return `false`.

**Example 1:**

```
**Input:** s = "00110110", k = 2
**Output:** true
**Explanation:** The binary codes of length 2 are "00", "01", "10" and "11". They can be all found as substrings at indicies 0, 1, 3 and 2 respectively.
```

**Example 2:**

```
**Input:** s = "00110", k = 2
**Output:** true
```

**Example 3:**

```
**Input:** s = "0110", k = 1
**Output:** true
**Explanation:** The binary codes of length 1 are "0" and "1", it is clear that both exist as a substring. 
```

**Example 4:**

```
**Input:** s = "0110", k = 2
**Output:** false
**Explanation:** The binary code "00" is of length 2 and doesn't exist in the array.
```

**Example 5:**

```
**Input:** s = "0000000001011100", k = 4
**Output:** false
```

**Constraints:**

* `1 <= s.length <= 5 * 105`
* `s[i]` is either `'0'` or `'1'`.
* `1 <= k <= 20`

## ac

```java
```