23-dec-2024-Task2.cpp

// 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.


class Solution
{
public:
    int minimumMoves(string s)
    {
        int count = 0;
        function<void(string)> findCount = [&count](string s)
        {
            if (s.find('X') != string::npos)
                ++count;
        };
        int size = s.size();
        for (int i = 0, j = 3; i < size;)
        {
            if (s[i] != 'X')
            {
                ++i, ++j;
                continue;
            }
            if (j < size)
                findCount(s.substr(i, 3));
            else
                findCount(s.substr(i));

            i = j;
            j += 3;
        }

        return count;
    }
};