Initial commit

2015/puzzle-12-02.cc

@@ -0,0 +1,65 @@
+#include <cassert>
+#include <cctype>
+#include <functional>
+#include <iostream>
+#include <map>
+#include <regex>
+#include <set>
+#include <string>
+#include <variant>
+
+int do_parse(std::string const &s, std::string::size_type &pos) {
+  int result = 0;
+  bool ignore = false;
+
+  while (pos < s.size()) {
+    if (s[pos] == '{') {
+      ++pos;
+      result += do_parse(s, pos);
+    } else if (s[pos] == '[') {
+      ++pos;
+      result += do_parse(s, pos);
+    } else if (s[pos] == '}') {
+      ++pos;
+      return ignore ? 0 : result;
+    } else if (s[pos] == ']') {
+      ++pos;
+      return result;
+    } else if (s[pos] == '"') {
+      ++pos;
+      auto e = s.find('"', pos);
+      assert(e != std::string::npos);
+      std::string v = s.substr(pos, e - pos);
+      if (v == "red") {
+        ignore = true;
+      }
+      pos = e + 1;
+    } else if (std::isdigit(s[pos]) || s[pos] == '-') {
+      std::size_t len = 0;
+      result += std::stoi(s.substr(pos), &len);
+      pos += len;
+    } else {
+      assert(s[pos] == ',' || s[pos] == ':');
+      ++pos;
+    }
+  }
+
+  return result;
+}
+
+int parse_numbers(std::string const &s) {
+  std::string::size_type pos = 0;
+  int result = do_parse(s, pos);
+  assert(pos == s.size());
+  return result;
+}
+
+int main(int argc, char **argv) {
+  int acc = 0;
+  for (std::string line; std::getline(std::cin, line);) {
+    acc += parse_numbers(line);
+  }
+
+  std::cout << "Accumulated value: " << acc << "\n";
+  return 0;
+}