second challange

.gitignore

@@ -0,0 +1 @@
+main

first_day/2/main.cpp

@@ -0,0 +1,56 @@
+#include <cstdlib>
+#include <fstream>
+#include <string>
+#include <vector>
+
+using namespace std;
+
+int translate_movement(const string &input) {
+
+  string symbol = input.substr(0, 1);
+  int ammount = stoi(input.substr(1));
+  return (symbol == "R") ? ammount : -ammount;
+}
+
+int normalize_number(int number) {
+  number %= 100;
+  if (number < 0)
+    number += 100;
+  return number;
+}
+
+int main() {
+  std::ifstream file("input.txt");
+  vector<string> data;
+  string s;
+  while (file >> s) {
+    data.push_back(s);
+  }
+
+  int count_zero = 0;
+  int pos = 50;
+
+  for (const string &movement : data) {
+    int delta = translate_movement(movement);
+
+    if (abs(delta) >= 100) {
+      int cycles = abs(delta) / 100;
+      delta = delta % 100;
+      count_zero += cycles;
+    }
+
+    int old_pos = pos;
+    pos = normalize_number(pos + delta);
+
+    if (delta > 0 && pos < old_pos) {
+      count_zero++;
+    }
+
+    if (delta < 0) {
+      if ((pos > old_pos && old_pos != 0) || pos == 0) {
+        count_zero++;
+      }
+    }
+  }
+  printf("Dial pointed at zero %d times.", count_zero);
+}