2027. Minimum Moves to Convert String

#### QUESTION:

You are given a string s consisting of n characters which are either ‘X’ or ‘O’.

A move is defined as selecting three consecutive characters of s and converting them to ‘O’. Note that if a move is applied to the character ‘O’, it will stay the same.

Return the minimum number of moves required so that all the characters of s are converted to ‘O’.

Example 1:

``````Input: s = "XXX"
Output: 1
Explanation: XXX -> OOO
We select all the 3 characters and convert them in one move.
``````

Example 2:

``````Input: s = "XXOX"
Output: 2
Explanation: XXOX -> OOOX -> OOOO
We select the first 3 characters in the first move, and convert them to 'O'.
Then we select the last 3 characters and convert them so that the final string contains all 'O's.
``````

Example 3:

``````Input: s = "OOOO"
Output: 0
Explanation: There are no 'X's in s to convert.
``````

Constraints:

``````3 <= s.length <= 1000
s[i] is either 'X' or 'O'.
``````

#### SOLUTION:

``````class Solution {
func minimumMoves(_ s: String) -> Int {
var arrS = Array(s)
var result = 0
for index in arrS.indices {
if arrS[index] == "X" {
arrS[index] = "O"
if index + 1 < arrS.count {
arrS[index+1] = "O"
}
if index + 2 < arrS.count {
arrS[index+2] = "O"
}
result += 1
}
}
return result
}
}
``````