Add <cassert> header include

This fixes some Linux build failures.

2016/puzzle-01-01.cc

@@ -2,6 +2,7 @@
 // Created by Matthew Gretton-Dann on 02/12/2021.
 //
 
+#include <cassert>
 #include <iostream>
 #include <string>
 
@@ -66,4 +67,4 @@ auto main() -> int
   vert = std::abs(vert);
   std::cout << "We end up " << horiz << " + " << vert << " = " << horiz + vert << " blocks away.\n";
   return 0;
-}
+}

2016/puzzle-01-02.cc

@@ -2,6 +2,7 @@
 // Created by Matthew Gretton-Dann on 02/12/2021.
 //
 
+#include <cassert>
 #include <iostream>
 #include <set>
 #include <string>
@@ -55,4 +56,4 @@ auto main() -> int
   }
   std::cerr << "Didn't find an answer.\n";
   return 1;
-}
+}

2016/puzzle-03-01.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <cctype>
 #include <iostream>
 #include <string>
@@ -45,4 +46,4 @@ auto main() -> int
   }
   std::cout << "Number of valid triangles: " << valid << '\n';
   return 0;
-}
+}

2016/puzzle-03-02.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <cctype>
 #include <iostream>
 #include <string>
@@ -63,4 +64,4 @@ auto main() -> int
       }
     }
   }
-}
+}

2016/puzzle-04-01.cc

@@ -2,6 +2,7 @@
 // Created by Matthew Gretton-Dann on 03/12/2021.
 //
 
+#include <cassert>
 #include <iostream>
 #include <map>
 #include <set>
@@ -87,4 +88,4 @@ auto main() -> int
 
   std::cout << "Sum of sector numbers: " << sum << '\n';
   return 0;
-}
+}

2016/puzzle-04-02.cc

@@ -2,6 +2,7 @@
 // Created by Matthew Gretton-Dann on 03/12/2021.
 //
 
+#include <cassert>
 #include <iostream>
 #include <map>
 #include <set>
@@ -103,4 +104,4 @@ auto main() -> int
 
   std::cout << "Sum of sector numbers: " << sum << '\n';
   return 0;
-}
+}

2016/puzzle-08-01.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <iostream>
 #include <numeric>
 #include <string>
@@ -97,4 +98,4 @@ auto main() -> int
 
   std::cout << "Number of lit fields: " << display.lit_count() << '\n';
   return 0;
-}
+}

2016/puzzle-08-02.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <iostream>
 #include <numeric>
 #include <string>
@@ -111,4 +112,4 @@ auto main() -> int
   std::cout << "Number of lit fields: " << display.lit_count() << '\n';
   display.print(std::cout);
   return 0;
-}
+}

2016/puzzle-09-01.cc

@@ -2,6 +2,7 @@
 // Created by Matthew Gretton-Dann on 05/12/2021.
 //
 
+#include <cassert>
 #include <iostream>
 #include <string>
 
@@ -56,4 +57,4 @@ auto main() -> int
   auto output{decompress(input)};
   std::cout << "Output length: " << output.size() << '\n';
   return 0;
-}
+}

2016/puzzle-09-02.cc

@@ -2,6 +2,7 @@
 // Created by Matthew Gretton-Dann on 05/12/2021.
 //
 
+#include <cassert>
 #include <iostream>
 #include <string>
 
@@ -53,4 +54,4 @@ auto main() -> int
   auto output{decompress_length(input)};
   std::cout << "Output length: " << output << '\n';
   return 0;
-}
+}

2016/puzzle-10-01.cc

@@ -3,6 +3,7 @@
 //
 
 #include <algorithm>
+#include <cassert>
 #include <iostream>
 #include <regex>
 #include <string>
@@ -129,4 +130,4 @@ auto main() -> int
       bot.clear();
     }
   }
-}
+}

2016/puzzle-10-02.cc

@@ -3,6 +3,7 @@
 //
 
 #include <algorithm>
+#include <cassert>
 #include <iostream>
 #include <regex>
 #include <string>
@@ -127,4 +128,4 @@ auto main() -> int
   }
 
   std::cout << "Result: " << outputs[0] * outputs[1] * outputs[2] << '\n';
-}
+}

2016/puzzle-14-01.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <iostream>
 #include <string>
 #include <string_view>

2016/puzzle-14-02.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <iostream>
 #include <string>
 #include <string_view>

2016/puzzle-17-01.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <iostream>
 #include <set>
 #include <string>

2016/puzzle-17-02.cc

@@ -3,6 +3,7 @@
 //
 
 #include <array>
+#include <cassert>
 #include <iostream>
 #include <set>
 #include <string>

2016/puzzle-20-02.cc

@@ -1,3 +1,4 @@
+#include <cassert>
 #include <iomanip>
 #include <iostream>
 #include <numeric>
@@ -98,4 +99,4 @@ auto main() -> int
   std::cout << "First available IP address: " << inverse.lowest() << '\n';
   std::cout << "Number of available IP addresses: " << inverse.count() << '\n';
   return 0;
-}
+}