Initial commit

2020/puzzle-02-02.cc

@@ -0,0 +1,51 @@
+#include <cassert>
+#include <iostream>
+#include <string>
+#include <vector>
+
+struct PasswordChecker {
+  PasswordChecker(std::string const &s) {
+    std::size_t pos = 0;
+    pos1_ = std::stoul(s, &pos, 10);
+    assert(s[pos] == '-');
+    std::string s2 = s.substr(pos + 1);
+    pos2_ = std::stoul(s2, &pos, 10);
+    assert(s2[pos] == ' ');
+    c_ = s2[pos + 1];
+    assert(s2[pos + 2] == ':');
+    assert(s2[pos + 3] == ' ');
+    password_ = s2.substr(pos + 4);
+  }
+
+  bool is_valid() const {
+    std::string::size_type count = 0;
+    if (password_.at(pos1_ - 1) == c_) {
+      ++count;
+    }
+    if (password_.at(pos2_ - 1) == c_) {
+      ++count;
+    }
+    return count == 1;
+  }
+
+  std::string::size_type pos1_; // 1 based
+  std::string::size_type pos2_; // 1 based
+  std::string::value_type c_;
+  std::string password_;
+};
+
+int main(int argc, char **argv) {
+  unsigned count = 0;
+  for (std::string line; std::getline(std::cin, line);) {
+    PasswordChecker check(line);
+    if (check.is_valid()) {
+      ++count;
+    } else {
+      std::cout << "IN";
+    }
+    std::cout << "VALID: " << line << "\n";
+  }
+
+  std::cout << "Number of valid: " << count << "\n";
+  return 0;
+}