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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

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