# Check if all the 1s in a binary string are equidistant or not in Python

Suppose we have a binary string str, we have to check whether all of the 1s in the string are equidistant or not. In other words, the distance between every two 1s is same. And the string contains at least two 1s.

So, if the input is like s = "100001000010000", then the output will be True as the 1s are at distance 4 from each other.

To solve this, we will follow these steps −

• index := a new list
• for i in range 0 to size of s, do
• if s[i] is same as 1, then
• insert i at the end of index
• t := size of index
• for i in range 1 to t - 1, do
• if (index[i] - index[i - 1]) is not same as (index - index), then
• return False
• return True

Let us see the following implementation to get better understanding −

## Example

Live Demo

def solve(s):
index = []
for i in range(len(s)):
if s[i] == '1':
index.append(i)
t = len(index)
for i in range(1, t):
if (index[i] - index[i - 1]) != (index - index):
return False
return True
s = "100001000010000"
print(solve(s))

## Input

"100001000010000"

## Output

True