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
}