README.md

2027. Minimum Moves to Convert String

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'.

Solutions (Rust)

1. Solution

impl Solution {
    pub fn minimum_moves(s: String) -> i32 {
        let s = s.as_bytes();
        let mut i = 0;
        let mut ret = 0;

        while i < s.len() {
            if s[i] == b'X' {
                i += 2;
                ret += 1;
            }
            i += 1;
        }

        ret
    }
}