2024 day 10

CMakeLists.txt

@@ -96,4 +96,6 @@ addday(06)
 addday(07)
 addday(08)
 addday(09)
+addday(10)
+
 #===============================================================================

README.md

@@ -338,7 +338,7 @@
 </details>
 
 <details><summary><a href="year2024">2024</a>
- :star: :star: :star: :star: :star: :star: :star: :star: :star: ✩
+ :star: :star: :star: :star: :star: :star: :star: :star: :star: :star:
  ✩ ✩ ✩ ✩ ✩ ✩ ✩ ✩ ✩ ✩
  ✩ ✩ ✩ ✩ ✩ 
 </summary>
@@ -360,6 +360,8 @@
   * [Day 8](year2024/day08) - Resonant Collinearity :star:
 
   * [Day 9](year2024/day09) - Disk Fragmenter :star:
+
+  * [Day 10](year2024/day10) - Hoof It :star:
 </details>
 
 Legend

year2024/day10/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.29)
+
+set(YEAR 2024)
+set(DAY 10)
+
+project("${YEAR} Day ${DAY}" LANGUAGES CXX)
+
+add_compile_definitions(DAY=day_${DAY})
+add_compile_definitions(YEAR=year_${YEAR})
+
+include_directories(..)
+include_directories(../..)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+add_executable(${YEAR}_day_${DAY} ../../main.cpp ../../aoc.cpp day_${DAY}.cpp input)

year2024/day10/day_10.cpp

@@ -0,0 +1,113 @@
+#include "day"
+
+//---------------------------------------------------------------------------//
+struct P {
+    int x,y;
+    size_t hash() const { return ((size_t)y<<32)|(size_t)x; }
+    bool operator==(const P& o ) const { return y==o.y && x==o.x; }
+};
+
+//---------------------------------------------------------------------------//
+
+template<>
+struct std::hash<P> {
+    size_t operator()( const P& p) const { return p.hash();}
+};
+
+//---------------------------------------------------------------------------//
+namespace aoc::YEAR::DAY {
+
+//---------------------------------------------------------------------------//
+// Test data
+std::string testinput (
+R"(89010123
+78121874
+87430965
+96549874
+45678903
+32019012
+01329801
+10456732
+)");
+
+//---------------------------------------------------------------------------//
+inline std::istream& test_input() {
+    static std::stringstream ss;
+    return ss = std::stringstream ( testinput );;
+}
+
+//---------------------------------------------------------------------------//
+auto load( std::istream& file ) {
+    ::std::vector<::std::string> ret;
+    ::std::string line;
+    while(::std::getline( file, line ))
+        ret.push_back ( line );
+
+    return ret;
+}
+
+//---------------------------------------------------------------------------//
+size_t go ( std::vector<std::string>& t, int x, int y, std::unordered_set<P>& p ) {
+    size_t ret = 0;
+    int h = t.size(), w = t[0].size();
+    auto c = t[y][x];
+    if ( c=='9' ) {
+        p.insert ( { x, y } );
+        return 1;
+    }
+
+    if ( x +1 <  w && c + 1 == t[y][x+1] ) ret += go ( t, x+1, y  , p );
+    if ( x -1 >= 0 && c + 1 == t[y][x-1] ) ret += go ( t, x-1, y  , p );
+    if ( y +1 <  h && c + 1 == t[y+1][x] ) ret += go ( t, x  , y+1, p );
+    if ( y -1 >= 0 && c + 1 == t[y-1][x] ) ret += go ( t, x  , y-1, p );
+
+    return ret;
+}
+
+//---------------------------------------------------------------------------//
+void Task_1 ( ::std::istream& puzzle_input ) {
+    auto ans=0ull;
+
+    //aoc::test_enable();
+
+    auto& file = aoc::is_test_enabled() ? test_input() : puzzle_input;
+    auto data = load( file );
+
+    for ( uint y = 0; y < data.size(); y++ ) {
+        for ( uint x = 0; x < data[0].size(); x++ ) {
+            if ( data[y][x] == '0' ) {
+                std::unordered_set<P> p;
+                go ( data, x, y, p );
+                ans += p.size();
+            }
+        }
+    }
+
+    OUT ( ans );
+}
+
+//---------------------------------------------------------------------------//
+void Task_2 ( ::std::istream& puzzle_input ) {
+    auto ans = 0ull;
+
+    //aoc::test_enable();
+
+    auto& file = aoc::is_test_enabled() ? test_input() : puzzle_input;
+    auto data = load( file );
+
+    for ( uint y = 0; y < data.size(); y++ ) {
+        for ( uint x = 0; x < data[0].size(); x++ ) {
+            if ( data[y][x] == '0' ) {
+                std::unordered_set<P> p;
+                ans += go ( data, x, y, p );
+            }
+        }
+    }
+
+    OUT ( ans );
+}
+
+//---------------------------------------------------------------------------//
+
+}
+//---------------------------------------------------------------------------//

year2024/day10/input

@@ -0,0 +1,52 @@
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