Submission #1400488

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Source Code Expand

import java.util.*;

public class Main {
	
	static int[] dp;
	static int N;
	static String S;
	
	static int dfs(int k){
		if(k>=N) return 0;
		if(dp[k]!=-1) return dp[k];
		int a=0,min=-1;
		for(int i=1;i<=3;i++){
			a=dfs(k+i);
			if(S.charAt(k)=='X') a++;
			if(min>a||min==-1) min=a;
		}
		return dp[k]=min;	
	}
	
	public static void main(String[] args){
		Scanner s=new Scanner(System.in);
		int N=s.nextInt();
		String S=s.next();
		
		dp=new int[N];
		for(int i=0;i<N;i++){
			dp[i]=-1;
		}
		System.out.println(dfs(0));
		
	}
}

Submission Info

Judge Result