From 21e1237e93703f632253f042bd5877998d81c507 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Mon, 23 Dec 2024 07:55:11 +0100
Subject: Day 23 2024

---
 2024/23/day23a.cpp | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 2024/23/day23a.cpp

(limited to '2024/23/day23a.cpp')

diff --git a/2024/23/day23a.cpp b/2024/23/day23a.cpp
new file mode 100644
index 0000000..048a724
--- /dev/null
+++ b/2024/23/day23a.cpp
@@ -0,0 +1,40 @@
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <map>
+#include <queue>
+#include <ranges>
+#include <set>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+set<int> computers;
+bool m[26*26][26*26];
+
+int index(char a, char b) { return (int)(a-'a') + 26*(int)(b-'a'); }
+bool t(int i) { return i % 26 == 't' - 'a'; }
+
+int main() {
+	string line;
+	while (getline(cin, line)) {
+		int i = index(line[0], line[1]);
+		int j = index(line[3], line[4]);
+		computers.insert(i);
+		computers.insert(j);
+		m[i][j] = m[j][i] = true;
+	}
+
+	vector cv(computers.begin(), computers.end());
+	int tot = 0;
+	for (unsigned i = 0; i < cv.size(); i++)
+		for (unsigned j = i+1; j < cv.size(); j++)
+			for (unsigned k = j+1; k < cv.size(); k++)
+				tot += m[cv[i]][cv[j]] && m[cv[j]][cv[k]] && m[cv[k]][cv[i]] &&
+				       (t(cv[i]) || t(cv[j]) || t(cv[k]));
+
+	cout << tot << endl;
+	return 0;
+}
-- 
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