926. Flip String to Monotone Increasing ⭐

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 <= 10^5

• s[i] is either '0' or '1'.

解題

func minFlipsMonoIncr(s string) int {
    res, count1 := 0,0 

    for i:=0; i<len(s); i++ {
        if s[i] == '0' {
            res++
        } else {
            count1++
        }

        res = min(res, count1)
    }

    return res
}

func min(a, b int) int {
    if a < b { return a }
    return b
}