Syntax error Program to find longest subarray of 1s after deleting one element using Python

Program to find longest subarray of 1s after deleting one element using Python

Suppose we have a binary array called nums, we can delete one element from it. We have to find the size of the longest non-empty subarray which is containing only 1's in the resulting array. If there is no such subarray, then return 0.

So, if the input is like nums = [1,0,1,1,1,0,1,1,0], then the output will be 5 because by removing 0 from position 5, we can get a subarray [1,1,1,1,1] there are five 1s.

To solve this, we will follow these steps −

  • if 0 is not in nums, then

    • return size of nums - 1

  • if 1 is not in nums, then

    • return 0

  • a := a new list

  • cnt := 0

  • for each i in nums, do

    • if i is same as 0, then

      • if cnt is not same as 0, then

        • insert cnt at the end of a

        • cnt := 0

      • insert i at the end of a

      • otherwise,

        • cnt := cnt + 1

  • if cnt is not same as 0, then

    • insert cnt at the end of a

  • Max := 0

  • for i in range 0 to size of a, do

    • if a[i] is not same as 0, then

      • go for next iteration

    • if a[i] is same as 0 and i is same as size of a - 1, then

      • Max := maximum of Max and a[i-1]

    • otherwise when a[i] is same as 0 and i is same as 0, then

      • Max := maximum of Max and a[i+1]

    • otherwise when a[i] is same as 0, then

      • Max := maximum of Max and (a[i+1]+a[i-1])

  • return Max

Example

 Live Demo

def solve(nums):
   if 0 not in nums:
      return len(nums)-1
   if 1 not in nums:
      return 0
      a = []
      cnt = 0
      for i in nums:
         if i == 0:
            if cnt != 0:
               a.append(cnt)
               cnt = 0
            a.append(i)
         else:
            cnt += 1
      if cnt!=0:
         a.append(cnt)
      Max = 0
      for i in range(len(a)):
         if a[i] != 0:
            continue
         if a[i] == 0 and i == len(a)-1:
            Max = max(Max,a[i-1])
         elif a[i] == 0 and i == 0:
            Max = max(Max,a[i+1])
         elif a[i] == 0:
            Max = max(Max,a[i+1]+a[i-1])
   return Max
nums = [1,0,1,1,1,0,1,1,0]
print(solve(nums))

Input

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

Output

5
Updated on: 2021-05-29T13:58:34+05:30

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