From 445c7a15750a6a2187f9b3ef0086aacffde644e4 Mon Sep 17 00:00:00 2001
From: rlapo213 <rlapo@naver.com>
Date: Wed, 3 Aug 2022 22:38:51 +0900
Subject: [PATCH] Greedy,,

---
 .../2138.cpp"                                 | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 "sources/rlapo213_\352\271\200\354\236\254\355\230\204/2138.cpp"

diff --git "a/sources/rlapo213_\352\271\200\354\236\254\355\230\204/2138.cpp" "b/sources/rlapo213_\352\271\200\354\236\254\355\230\204/2138.cpp"
new file mode 100644
index 0000000..5a5804e
--- /dev/null
+++ "b/sources/rlapo213_\352\271\200\354\236\254\355\230\204/2138.cpp"
@@ -0,0 +1,60 @@
+#include<bits/stdc++.h>
+using namespace std;
+int n, cnt;
+bool a[100004];
+bool b[100004];
+bool c[100004];
+
+bool s() {
+	for (int i = 0; i < n; i++) {
+		if (a[i] != b[i])
+			return false;
+	}
+	return true;
+}
+
+int main() {
+	cin >> n;
+	for (int i = 0; i < n; i++) {
+		scanf("%1d", &c[i]);
+	}
+	for (int i = 0; i < n; i++) {
+		scanf("%1d", &b[i]);
+	}
+	//그냥 어렵게 생각하지말고
+	//맨앞 맨뒤 2개는 bitmask로 돌리고 스위치를 i 누르면 i+1, i+2 바뀐다고 생각하면
+	//한 칸 넘어가면 바꿀 수 없으니까 다르면 바꾸는 식으로
+
+	for (int u = 0; u < (1 << 2); u++) {
+		for (int i = 0; i < n; i++)
+			a[i] = c[i];
+		cnt = 0;
+		if (u & (1 << 0)) {
+			a[0] = !a[0];
+			a[1] = !a[1];
+			cnt++;
+		}
+		if (u & (1 << 1)) {
+			a[n - 1] = !a[n - 1];
+			a[n - 2] = !a[n - 2];
+			cnt++;
+		}
+		for (int i = 0; i < n - 2; i++) {
+			if (a[i] != b[i]) {
+				a[i] = !a[i];
+				a[i + 1] = !a[i + 1];
+				a[i + 2] = !a[i + 2];
+				cnt++;
+			}
+		}
+
+		if (s()) {
+			cout << cnt;
+			return 0;
+		}
+
+	}
+
+	cout << -1;
+	return 0;
+}
\ No newline at end of file