[PS][그리디]/[BOJ][15729][방탈출]

boj15729.cpp

#include <iostream>
using namespace std;

int n;
int cur[1000000];
int btn[1000000];

void show(void) {
	for (int i = 0; i < n; i++) {
		cout << cur[i] << ' ';
	}
	cout << "\n";
}

void press(int x) {
	for (int j = x; j < x + 3; j++) {
		if (j >= n) break;
		cur[j] = !cur[j];
	}
}

int main(void) { 
	cin >> n;
	for (int i = 0; i < n; i++) cin >> btn[i];
	int save = 0, i=0, ans=0;
	while (i< n) {
		for (; i < n; i++) {
			if (cur[i] == btn[i]) continue;
			press(i);
			ans++;
			//show();
		}
	}
	cout << ans << "\n";
	return 0;
}