[20251203] BOJ / G4 / 감시 카메라 / 권혁준

Author: oncsr

khj20006/202512/03 BOJ G4 감시 카메라.md

@@ -0,0 +1,41 @@
+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+
+int N;
+map<int, set<int>> X, Y;
+
+int main() {
+	cin.tie(0)->sync_with_stdio(0);
+
+	cin >> N;
+	for (int i = 0, x, y; i < N; i++) {
+		cin >> x >> y;
+		X[x].insert(y);
+		Y[y].insert(x);
+	}
+
+	if (min(X.size(), Y.size()) <= 3) return cout << 1, 0;
+
+	for (auto [x, v] : X) {
+		for (int i : v) {
+			Y[i].erase(x);
+			if (Y[i].empty()) Y.erase(i);
+		}
+		if (Y.size() <= 2) return cout << 1, 0;
+		for (int i : v) Y[i].insert(x);
+	}
+
+	for (auto [y, v] : Y) {
+		for (int i : v) {
+			X[i].erase(y);
+			if (X[i].empty()) X.erase(i);
+		}
+		if (X.size() <= 2) return cout << 1, 0;
+		for (int i : v) X[i].insert(y);
+	}
+
+	cout << 0;
+
+}
+```