Day 5 2024

6 files changed, 163 insertions, 1 deletions

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
--- /dev/null
+++ b/2024/05/b.out
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;
 }