day1 c++ 🤮

Author: rene-d

2024/README.md

@@ -9,6 +9,6 @@
 
 Puzzle                                                           | Stars | Languages
 ---------------------------------------------------------------- | ----- | -----------
-[Day 1: Historian Hysteria](https://adventofcode.com/2024/day/1) | ⭐⭐  | [Rust](../2024/day1/day1.rs) [Python](../2024/day1/day1.py) [C](../2024/day1/day1.c) [Go](../2024/day1/day1.go) [Ruby](../2024/day1/day1.rb) [JS](../2024/day1/day1.js) [Bash](../2024/day1/day1.sh) [Lua](../2024/day1/day1.lua) [C#](../2024/day1/day1.cs)
+[Day 1: Historian Hysteria](https://adventofcode.com/2024/day/1) | ⭐⭐  | [Rust](../2024/day1/day1.rs) [Python](../2024/day1/day1.py) [C](../2024/day1/day1.c) [C++](../2024/day1/day1.cpp) [Go](../2024/day1/day1.go) [Ruby](../2024/day1/day1.rb) [JS](../2024/day1/day1.js) [Bash](../2024/day1/day1.sh) [Lua](../2024/day1/day1.lua) [C#](../2024/day1/day1.cs)
 [Day 2: Red-Nosed Reports](https://adventofcode.com/2024/day/2)  | ⭐⭐  | [Rust](../2024/day2/day2.rs) [Python](../2024/day2/day2.py)
 [Day 3: Mull It Over](https://adventofcode.com/2024/day/3)       | ⭐⭐  | [Rust](../2024/day3/day3.rs) [Python](../2024/day3/day3.py)

2024/day1/day1.cpp

@@ -0,0 +1,76 @@
+// c++ -Wall -Wextra -Werror -std=c++23 -O2 -o day1 day1.cpp
+
+#include <vector>
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <ranges>
+#include <map>
+#include <algorithm>
+#include <inttypes.h>
+
+static void read_data(const char *filename, std::vector<int> &left, std::vector<int> &right)
+{
+    std::ifstream f;
+    std::string line;
+
+    f.open(filename);
+
+    if (!f.is_open())
+    {
+        throw std::logic_error("bad filename");
+    }
+
+    while (!f.eof())
+    {
+        int a, b;
+        f >> a >> b;
+
+        if (!f.fail())
+        {
+            left.push_back(a);
+            right.push_back(b);
+        }
+    }
+
+    f.close();
+}
+
+int main(int argc, char *argv[])
+{
+    std::vector<int> left, right;
+
+    if (argc >= 2)
+        read_data(argv[1], left, right);
+    else
+        read_data("input.txt", left, right);
+
+    std::sort(left.begin(), left.end());
+    std::sort(right.begin(), right.end());
+
+    // part 1
+
+    int part1 = 0;
+    for (auto [a, b] : std::views::zip(left, right)) // C++23
+    {
+        part1 += abs(a - b);
+    }
+    std::cout << part1 << std::endl;
+
+    // part 2
+
+    std::map<int, int> counter;
+    for (auto b : right)
+    {
+        counter[b] += 1;
+    }
+
+    int part2 = 0;
+    for (auto a : left)
+    {
+        part2 += a * counter[a];
+    }
+    std::cout << part2 << std::endl;
+
+    return 0;
+}

README.md

@@ -12,7 +12,7 @@ Made for fun 😎 and to practice Rust. Many thanks to [Eric Wastl](https://twit
 
 Puzzle                                                           | Stars | Languages
 ---------------------------------------------------------------- | ----- | -----------
-[Day 1: Historian Hysteria](https://adventofcode.com/2024/day/1) | ⭐⭐  | [Rust](2024/day1/day1.rs) [Python](2024/day1/day1.py) [C](../2024/day1/day1.c) [Go](../2024/day1/day1.go)
+[Day 1: Historian Hysteria](https://adventofcode.com/2024/day/1) | ⭐⭐  | [Rust](2024/day1/day1.rs) [Python](2024/day1/day1.py) [C](2024/day1/day1.c) [C++](2024/day1/day1.cpp) [Go](2024/day1/day1.go)
 [Day 2: Red-Nosed Reports](https://adventofcode.com/2024/day/2)  | ⭐⭐  | [Rust](2024/day2/day2.rs) [Python](2024/day2/day2.py)
 [Day 3: Mull It Over](https://adventofcode.com/2024/day/3)       | ⭐⭐  | [Rust](2024/day3/day3.rs) [Python](2024/day3/day3.py)
 

scripts/answers.py

@@ -662,14 +662,14 @@ def parse(_self, year, _day):
                     files.extend(f"[Rust]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".rs")
                     files.extend(f"[Python]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".py")
 
-                    files.extend(f"[C](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".c")
-                    files.extend(f"[C++](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".cpp")
-                    files.extend(f"[Go](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".go")
-                    # files.extend(f"[Ruby](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".rb")
-                    # files.extend(f"[JS](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".js")
-                    # files.extend(f"[Bash](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".sh")
-                    # files.extend(f"[Lua](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".lua")
-                    # files.extend(f"[C#](../{year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".cs")
+                    files.extend(f"[C]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".c")
+                    files.extend(f"[C++]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".cpp")
+                    files.extend(f"[Go]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".go")
+                    # files.extend(f"[Ruby]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".rb")
+                    # files.extend(f"[JS]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".js")
+                    # files.extend(f"[Bash]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".sh")
+                    # files.extend(f"[Lua]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".lua")
+                    # files.extend(f"[C#]({year}/{f.relative_to(year_dir)})" for f in sols if f.suffix == ".cs")
 
                     files = " ".join(files)