2027. Minimum Moves to Convert String

Problem Statement

Pattern:

---

Solution

public int minimumMoves(String s) {
	int steps = 0, i = 0, len = s.length();
	while (i < len) {
		if (s.charAt(i) == 'X') { steps++; i+=2; }
		i++;
	}
	return steps;
}

TC : $O(n)$ SC : $O(1)$

Notes

• This is a very simple slightly unintuitive greedy approach problem just like Police and Thieves
• You can visualise this as iterating forwards, by the left end of a 3 element long underline/bar. and with every single step we take, we try to take out the maximum number of X's we can without leaving out a single one!