[BOJ] 15729번 방탈출

문제

www.acmicpc.net/problem/15729

15729번: 방탈출

풀이

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;


public class Main {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		StringTokenizer st;
		int N = Integer.parseInt(br.readLine());
		int[] btn = new int[N+2];
		int cnt=0;
		st = new StringTokenizer(br.readLine());
		for(int i=0;i<N;i++)
			btn[i] = Integer.parseInt(st.nextToken());
		
		for(int i=0;i<N;i++) {
			if(btn[i]==1) {
				cnt++;
				if(btn[i+1]==0)
					btn[i+1] = 1;
				else
					btn[i+1]=0;
				if(btn[i+2]==0)
					btn[i+2] = 1;
				else
					btn[i+2]=0;
			}
		}
		System.out.println(cnt);
	}
}