Added day 3 (bleah)

1 files changed, 48 insertions, 0 deletions

diff --git a/2024/03/day03a.cpp b/2024/03/day03a.cpp
new file mode 100644
index 0000000..2fb04cf
--- /dev/null
+++ b/2024/03/day03a.cpp
@@ -0,0 +1,48 @@
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+int trymult(const string_view &s) {
+        if (s.substr(0, 4) != "mul(")
+                return 0;
+
+        auto t = s.substr(4, s.length()-4);
+
+        int x = 0, y = 0;
+        int i = 0;
+        for (; i < 3; i++)
+                if (t[i] >= '0' && t[i] <= '9')
+                        x = (x*10) + t[i]-'0';
+                else break;
+        if (i == 0 || t[i] != ',')
+                return 0;
+        i++;
+        int j = 0;
+        for (; j < 3; j++)
+                if (t[i+j] >= '0' && t[i+j] <= '9')
+                        y = (y*10) + t[i+j]-'0';
+                else break;
+        if (j == 0 || t[j+i] != ')')
+                return 0;
+        return x*y;
+}
+
+int mults(const string &line) {
+        int result = 0;
+        for (auto i = line.begin(); i != line.end(); i++)
+                result += trymult(string_view(i, line.end()));
+        return result;
+}
+
+int main() {
+        string line;
+        int result = 0;
+        while (cin >> line)
+                result += mults(line);
+        cout << result << endl;
+        return 0;
+}