From a937350ab20adc0f8172c4d99f4d711e92dfd947 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Thu, 5 Dec 2024 08:02:45 +0100
Subject: Day 5 2024

---
 2024/05/Makefile   |  24 ++++++++++++++++
 2024/05/b.out      | Bin 0 -> 171240 bytes
 2024/05/day05a.cpp |  53 ++++++++++++++++++++++++++++++++++
 2024/05/day05b.cpp |  83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2024/learned.txt   |   1 +
 2024/template.cpp  |   3 +-
 6 files changed, 163 insertions(+), 1 deletion(-)
 create mode 100644 2024/05/Makefile
 create mode 100755 2024/05/b.out
 create mode 100644 2024/05/day05a.cpp
 create mode 100644 2024/05/day05b.cpp

diff --git a/2024/05/Makefile b/2024/05/Makefile
new file mode 100644
index 0000000..f9ca961
--- /dev/null
+++ b/2024/05/Makefile
@@ -0,0 +1,24 @@
+CC=g++ -std=c++20 -g -Wall
+
+a:
+	${CC} -o a.out day05a.cpp
+
+b:
+	${CC} -o b.out day05b.cpp
+
+clean:
+	rm -f a b
+
+atest: a
+	./a.out
+
+btest: b
+	./b.out
+
+arun: a
+	./a.out < input
+
+brun: b
+	./b.out < input
+
+.PHONY: a b clean atest btest arun brun
diff --git a/2024/05/b.out b/2024/05/b.out
new file mode 100755
index 0000000..6676a53
Binary files /dev/null and b/2024/05/b.out differ
diff --git a/2024/05/day05a.cpp b/2024/05/day05a.cpp
new file mode 100644
index 0000000..be2037e
--- /dev/null
+++ b/2024/05/day05a.cpp
@@ -0,0 +1,53 @@
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+vector<int> readints(string &s) {
+	vector<int> v;
+	stringstream sin(s);
+	int x;
+
+	while (sin >> x)
+		v.push_back(x);
+
+	return v;
+}
+
+bool valid(vector<int> &v, vector<pair<int, int>> &rules) {
+	for (unsigned i = 0; i < v.size(); i++)
+		for (unsigned j = i+1; j < v.size(); j++)
+			for (auto r : rules)
+				if (v[i] == r.second && v[j] == r.first)
+					return false;
+	return true;
+}
+
+int main() {
+	string line;
+	vector<pair<int, int>> rules;
+	while (getline(cin, line)) {
+		if (line == "")
+			break;
+
+		replace(line.begin(), line.end(), '|', ' ');
+		auto v = readints(line);
+		int x = v[0];
+		int y = v[1];
+		rules.push_back(make_pair(x, y));
+	}
+
+
+	int tot = 0;
+	while (getline(cin, line)) {
+		replace(line.begin(), line.end(), ',', ' ');
+		auto v = readints(line);
+		if (valid(v, rules))
+			tot += v[v.size()/2];
+	}
+	cout << tot << endl;
+	return 0;
+}
diff --git a/2024/05/day05b.cpp b/2024/05/day05b.cpp
new file mode 100644
index 0000000..d9168ac
--- /dev/null
+++ b/2024/05/day05b.cpp
@@ -0,0 +1,83 @@
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <set>
+#include <vector>
+using namespace std;
+
+vector<int> readints(string &s) {
+	vector<int> v;
+	stringstream sin(s);
+	int x;
+
+	while (sin >> x)
+		v.push_back(x);
+
+	return v;
+}
+
+bool valid(vector<int> &v, vector<pair<int, int>> &rules) {
+	for (unsigned i = 0; i < v.size(); i++)
+		for (unsigned j = i+1; j < v.size(); j++)
+			for (auto r : rules)
+				if (v[i] == r.second && v[j] == r.first)
+					return false;
+	return true;
+}
+
+bool canbenext(int x, vector<int> &v, bool picked[], vector<pair<int, int>> &rules) {
+	for (unsigned i = 0; i < v.size(); i++) {
+		if (picked[i])
+			continue;
+		for (auto r : rules)
+			if (r.first == v[i] && r.second == x)
+				return false;
+	}
+
+	return true;
+}
+
+vector<int> sort(vector<int> &v, vector<pair<int, int>> &rules) {
+	vector<int> w;
+	bool picked[v.size()] = { 0 };
+
+	while (w.size() < v.size()) {
+		for (unsigned i = 0; i < v.size(); i++) {
+			if (!picked[i] && canbenext(v[i], v, picked, rules)) {
+				picked[i] = true;
+				w.push_back(v[i]);
+			}
+		}
+	}
+
+	return w;
+}
+
+int main() {
+	string line;
+	vector<pair<int, int>> rules;
+	while (getline(cin, line)) {
+		if (line == "")
+			break;
+
+		replace(line.begin(), line.end(), '|', ' ');
+		auto v = readints(line);
+		int x = v[0];
+		int y = v[1];
+		rules.push_back(make_pair(x, y));
+	}
+
+	int tot = 0;
+	while (getline(cin, line)) {
+		replace(line.begin(), line.end(), ',', ' ');
+		auto v = readints(line);
+		if (!valid(v, rules)) {
+			auto w = sort(v, rules);
+			tot += w[w.size()/2];
+		}
+	}
+	cout << tot << endl;
+	return 0;
+}
diff --git a/2024/learned.txt b/2024/learned.txt
index 4ab29b1..3a01fc0 100644
--- a/2024/learned.txt
+++ b/2024/learned.txt
@@ -5,3 +5,4 @@ List of things I learned (or refreshed) with this year's AoC.
 * Day 3: std::string_view
 * Day 4: nothing special, some practice with classic and a weird trick
   to assign two variables at once with a pair of references pair<int&, int&>
+* Day 5: std::find and std::replace
diff --git a/2024/template.cpp b/2024/template.cpp
index 3707052..7508a23 100644
--- a/2024/template.cpp
+++ b/2024/template.cpp
@@ -7,7 +7,8 @@
 using namespace std;
 
 int main() {
-	while (cin >> TODO)
+	string line;
+	while (getline(cin, line))
 		;
 	return 0;
 }
-- 
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