README_EN.md

2027. Minimum Moves to Convert String

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Description

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

Python3

class Solution:
    def minimumMoves(self, s: str) -> int:
        ans = i = 0
        while i < len(s):
            if s[i] == "X":
                ans += 1
                i += 3
            else:
                i += 1
        return ans

Java

class Solution {
    public int minimumMoves(String s) {
        int ans = 0;
        for (int i = 0; i < s.length(); ++i) {
            if (s.charAt(i) == 'X') {
                ++ans;
                i += 2;
            }
        }
        return ans;
    }
}

C++

class Solution {
public:
    int minimumMoves(string s) {
        int ans = 0;
        for (int i = 0; i < s.size(); ++i) {
            if (s[i] == 'X') {
                ++ans;
                i += 2;
            }
        }
        return ans;
    }
};

Go

func minimumMoves(s string) int {
	ans := 0
	for i := 0; i < len(s); i++ {
		if s[i] == 'X' {
			ans++
			i += 2
		}
	}
	return ans
}

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