# Check if a key is present in every segment of size k in an array in Python

Suppose we have an array A with N elements, we have another value p and a segment size k, we have to check whether key p is present in every segment of size k in A.

So, if the input is like A = [4, 6, 3, 5, 10, 4, 2, 8, 4, 12, 13, 4], p = 4 and k = 3, then the output will be True

To solve this, we will follow these steps −

• i := 0
• while i < n is non-zero, do
• j := 0
• while j < k, do
• if arr[j + i] is same as p, then
• break
• j := j + 1
• if j is same as k, then
• return False
• i := i + k
• if i is same as n, then
• return True
• j := i - k
• while j < n, do
• if arr[j] is same as p, then
• break
• j := j + 1
• if j is same as n, then
• return False
• return True

## Example

Let us see the following implementation to get better understanding −

Live Demo

def key_in_segment_k(arr, p, k, n) :
i = 0
while i < n :
j = 0
while j < k :
if arr[j + i] == p :
break
j += 1
if j == k :
return False
i = i + k
if i == n :
return True
j = i - k
while j < n :
if arr[j] == p :
break
j += 1
if j == n :
return False
return True
arr = [4, 6, 3, 5, 10, 4, 2, 8, 4, 12, 13, 4]
p, k = 4, 3
n = len(arr)
print(key_in_segment_k(arr, p, k, n))

## Input

[4, 6, 3, 5, 10, 4, 2, 8, 4, 12, 13, 4]

## Output

True