Day 5

d5/main.cxx

@@ -0,0 +1,51 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <vector>
+#include <map>
+#include <algorithm>
+
+int main()
+{
+  std::ifstream file{"../d5/input.txt"};
+
+  std::vector<std::string> input;
+  std::string line, ignore;
+  while (std::getline(file, line))
+    input.push_back(line);
+
+  const auto it = std::find_if(input.begin(), input.end(), [&](const auto &l)
+                               { return l[1] == '1'; });
+  const int crateVerLen = it - input.begin();
+  const int crateHorLen = input[0].size();
+  std::map<int, std::stack<char>> crates{};
+
+  for (int i{crateVerLen - 1}; i >= 0; i--)
+    for (int j{1}; j < crateHorLen; j += 4)
+      if (input[i][j] != ' ')
+        crates[(j / 4) + 1].push(input[i][j]);
+
+  for (int i{crateVerLen + 2}; i < input.size(); i++)
+  {
+    std::stringstream iss(input[i]);
+    int amount, from, to;
+    iss >> ignore >> amount >> ignore >> from >> ignore >> to;
+
+    std::vector<char> cs{};
+    for (int j{0}; j < amount; j++)
+    {
+      cs.push_back(crates[from].top());
+      crates[from].pop();
+    }
+    for (int j = cs.size() - 1; j >= 0; j--)
+      crates[to].push(cs[j]);
+  }
+
+  for (auto &[_, cs] : crates)
+    std::cout << cs.top();
+
+  std::cout << std::endl;
+
+  return 0;
+}