From 94d3ffe921b1dfae165902f16b49cbcec150574f Mon Sep 17 00:00:00 2001
From: Pratchaya Khansomboon <pratchak@axis.com>
Date: Mon, 2 Dec 2024 14:41:42 +0100
Subject: [PATCH] aoc24: day01 update to zip

Include Linux command stuff to use clang compiler.
---
 README.md | 6 ++++++
 aoc.cpp   | 9 +++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 33e7db8..823f762 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,12 @@ Symlink `compile_commands.json` to root directory for `ccls`/`clangd`.
 ln -sfn ./build/compile_commands.json .
 ```
 
+**Linux (use clang)**
+
+```sh
+CC=clang CXX=clang++ cmake -S . -Bbuild -GNinja -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_FLAGS="-stdlib=libc++ -I$HOME/.local/include/c++/v1" -DCMAKE_EXE_LINKER_FLAGS="-stdlib=libc++ -fuse-ld=lld -L$HOME/.local/lib" -DCMAKE_SHARED_LINKER_FLAGS="-stdlib=libc++ -fuse-ld=lld -L$HOME/.local/lib"
+```
+
 **Windows (requires admin)**
 
 ```sh
diff --git a/aoc.cpp b/aoc.cpp
index e1517d9..b45031c 100644
--- a/aoc.cpp
+++ b/aoc.cpp
@@ -48,11 +48,12 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
     std::sort(std::begin(a), std::end(a));
     std::sort(std::begin(b), std::end(b));
 
-    auto diff_view = std::views::zip_transform([](auto a, auto b) {
-        return a > b ? a - b : b - a;
-    }, a, b);
-
+    auto diff_view = std::views::zip(a, b) | std::views::transform([](auto const& p) {
+        auto const [x, y] = p;
+        return x > y ? x - y : y - x;
+    });
     auto const sum = std::accumulate(std::begin(diff_view), std::end(diff_view), 0);
+
     fmt::print("Part A: {}\n", std::abs(sum));
 
     auto values = a | std::views::transform([&b](auto v) {