# Program to find length of longest set of 1s by flipping k bits in Python

Suppose we have a binary list, so here only 1s and 0s are available and we also have another number k. We can set at most k 0s to 1s, we have to find the length of the longest sublist containing all 1s.

So, if the input is like nums = [0, 1, 1, 0, 0, 1, 1] k = 2, then the output will be 6, as we can set the two middle 0s to 1s and then the list becomes [0, 1, 1, 1, 1, 1, 1].

To solve this, we will follow these steps −

• zeros := 0, ans := 0, j := 0
• for each index i and value n in nums, do
• zeros := zeros + (1 when n is same as 0, otherwise 0)
• while zeros > k, do
• zeros := zeros - (1 when nums[j] is same as 0, otherwise 0)
• j := j + 1
• if i - j + 1 > ans, then
• ans := i - j + 1
• return ans

Let us see the following implementation to get better understanding −

## Example

Live Demo

class Solution:
def solve(self, nums, k):
zeros = 0
ans = 0
j = 0
for i, n in enumerate(nums):
zeros += n == 0
while zeros > k:
zeros -= nums[j] == 0
j += 1
if i - j + 1 > ans:
ans = i - j + 1
return ans
ob = Solution()
nums = [0, 1, 1, 0, 0, 1, 1]
k = 2
print(ob.solve(nums, k))

## Input

[0, 1, 1, 0, 0, 1, 1], 2

## Output

6

Updated on: 19-Nov-2020

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