Flip string to monotone increasing

class Solution:
    def minFlipsMonoIncr(self, s: str) -> int:
        dp = [[0, 0] for _ in range(len(s))]
        dp[0][0] = 0 if s[0] == '0' else 1
        dp[0][1] = 0 if s[0] == '1' else 1
        for i in range(1, len(s)):

            dp[i][0] = dp[i - 1][0] + (0 if s[i] == '0' else 1)
            dp[i][1] = min(
                dp[i - 1][0],
                dp[i - 1][1] + (0 if s[i] == '1' else 1)
            )
        # print(dp)

        return min(dp[-1][0], dp[-1][1])

Flip String to Monotone Increasing

Difficulty: Medium


A binary string is monotone increasing if it consists of some number of 0's (possibly none), followed by some number of 1's (also possibly none).

You are given a binary string s. You can flip s[i] changing it from 0 to 1 or from 1 to 0.

Return the minimum number of flips to make s monotone increasing.

 

Example 1:

Input: s = "00110"
Output: 1
Explanation: We flip the last digit to get 00111.

Example 2:

Input: s = "010110"
Output: 2
Explanation: We flip to get 011111, or alternatively 000111.

Example 3:

Input: s = "00011000"
Output: 2
Explanation: We flip to get 00000000.

 

Constraints:

  • 1 <= s.length <= 105
  • s[i] is either '0' or '1'.