4 files changed, 102 insertions, 0 deletions

diff --git a/2024/02/Makefile b/2024/02/Makefile
new file mode 100644
index 0000000..c3cdac5
--- /dev/null
+++ b/2024/02/Makefile
@@ -0,0 +1,24 @@
+CC=g++ -std=c++20 -g -Wall
+
+a:
+        ${CC} -o a.out day02a.cpp
+
+b:
+        ${CC} -o b.out day02b.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/2024/02/b.out b/2024/02/b.out
new file mode 100755
index 0000000..fc29aef
--- /dev/null
+++ b/2024/02/b.out
diff --git a/2024/02/day02a.cpp b/2024/02/day02a.cpp
new file mode 100644
index 0000000..cdd9efa
--- /dev/null
+++ b/2024/02/day02a.cpp
@@ -0,0 +1,30 @@
+#include <iostream>
+#include <sstream>
+#include <vector>
+#include <algorithm>
+#include <string>
+using namespace std;
+
+bool isvalid(const string &line) {
+        int x, y, b;
+        istringstream s(line);
+
+        s >> x >> y;
+        b = x > y ? 1 : -1;
+        do {
+                int d = b * (x-y);
+                if (d < 1 || d > 3)
+                        return false;
+                x = y;
+        } while (s >> y);
+
+        return true;
+}
+
+int main() {
+        int tot = 0;
+        for (string line; getline(cin, line); )
+                tot += isvalid(line);
+        cout << tot << endl;
+        return 0;
+}
diff --git a/2024/02/day02b.cpp b/2024/02/day02b.cpp
new file mode 100644
index 0000000..2e3dcf4
--- /dev/null
+++ b/2024/02/day02b.cpp
@@ -0,0 +1,48 @@
+#include <iostream>
+#include <sstream>
+#include <vector>
+#include <algorithm>
+#include <string>
+using namespace std;
+
+bool isvalid_v(const vector<int> &v) {
+        int b = v[0] > v[1] ? 1 : -1;
+        for (unsigned i = 0; i < v.size()-1; i++) {
+                int d = b * (v[i] - v[i+1]);
+                if (d < 1 || d > 3)
+                        return false;
+        }
+        return true;
+}
+
+vector<int> getv(const string &line) {
+        int x;
+        vector<int> ret;
+        istringstream s(line);
+
+        while(s >> x)
+                ret.push_back(x);
+
+        return ret;
+}
+
+bool isvalid(const string &line) {
+        vector v0 = getv(line);
+        if (isvalid_v(v0))
+                return true;
+        for (unsigned i = 0; i < v0.size(); i++) {
+                vector v = v0;
+                v.erase(v.begin() + i);
+                if (isvalid_v(v))
+                        return true;
+        }
+        return false;
+}
+
+int main() {
+        int tot = 0;
+        for (string line; getline(cin, line); )
+                tot += isvalid(line);
+        cout << tot << endl;
+        return 0;
+}