Add C++ specialized Dockerfile

[toshi0806]

Summary

C++競技プログラミング専用の Dockerfile.cpp を作成しました。

Changes

• ✅ Dockerfile.cpp を新規作成
  • C++ とそのライブラリのみに特化
  • 他言語サポート（Python, Ruby, Node.js, Java, Erlang, Elixir, Rust）を全て削除
  • マルチステージビルドで最適化

Included C++ Libraries

toml/config.toml の設定に基づき、以下のライブラリを含めています:

• GCC 15.2.0
• Boost 1.88.0
• Abseil 20250512.1
• LibTorch 2.8.0
• OR-Tools 9.14
• Eigen 3.4.0
• Z3 4.15.2
• AC Library 1.6
• range-v3 0.12.0
• unordered_dense 4.5.0
• immer 0.8.1
• LightGBM 4.6.0
• GMP 6.3.0

Usage

# Build
docker build -t atcoder-container:cpp -f Dockerfile.cpp .

# Compile C++ code
docker run --rm -v $(pwd):/work -w /work atcoder-container:cpp atcoder-compile Main.cpp

# Run
docker run --rm -v $(pwd):/work -w /work atcoder-container:cpp ./a.out

Resolves #18

[Copilot]

Pull Request Overview

This PR introduces a specialized C++-only Dockerfile (Dockerfile.cpp) for competitive programming on AtCoder, removing support for other languages (Python, Ruby, Node.js, Java, Erlang, Elixir, Rust) and optimizing the build using multi-stage compilation.

Key Changes:

• Multi-stage Docker build separating compilation (builder) from runtime environment
• Installation of 13 C++ libraries including GCC 15.2.0, Boost 1.88.0, and various competitive programming tools
• Custom atcoder-compile script with comprehensive compiler flags and library linking

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[Copilot]

Pull Request Overview

Copilot reviewed 10 out of 27 changed files in this pull request and generated 1 comment.

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[Copilot]

[nitpick] The C++ test code embedded in the shell script is missing proper indentation and formatting. Consider using a here-document with proper escaping for better readability and maintainability.

Suggested change

	echo '#include <iostream>
	int main() { std::cout << "Hello AtCoder" << std::endl; return 0; }' > /tmp/test.cpp
	cat << 'EOF' > /tmp/test.cpp
	#include <iostream>
	int main() {
	std::cout << "Hello AtCoder" << std::endl;
	return 0;
	}
	EOF

[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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[Copilot]

The string replacement pattern '/opt/' uses hardcoded path prefix that may not match AC_INSTALL_DIR. Consider using a more robust path manipulation or verify AC_INSTALL_DIR always starts with /opt/.

Suggested change

	CMAKE_PATH="${AC_INSTALL_DIR/'/opt/'/}/include" && \
	CMAKE_PATH="${AC_INSTALL_DIR#/opt/}/include" && \

[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

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[Copilot]

The wget command is missing the -q flag for quiet output, which is inconsistent with other download commands in this Dockerfile (lines 52, 85, 112, 121, 186, 214, 249, 281). Add -q flag for consistency and cleaner build logs.

Suggested change

	RUN wget "https://download.pytorch.org/libtorch/cpu/libtorch-shared-with-deps-$LIBTORCH_VERSION%2Bcpu.zip" -O libtorch.zip && \
	RUN wget -q "https://download.pytorch.org/libtorch/cpu/libtorch-shared-with-deps-$LIBTORCH_VERSION%2Bcpu.zip" -O libtorch.zip && \

[Copilot]

The wget command is missing the -q flag for quiet output, which is inconsistent with other download commands in this Dockerfile. Add -q flag for consistency with lines 52, 85, 112, 121, 186, 214, 249, and 281.

Suggested change

	RUN wget "https://github.com/martinus/unordered_dense/archive/refs/tags/v$UNORDERED_DENSE_VERSION.tar.gz" -O unordered_dense.tar.gz && \
	RUN wget -q "https://github.com/martinus/unordered_dense/archive/refs/tags/v$UNORDERED_DENSE_VERSION.tar.gz" -O unordered_dense.tar.gz && \

[Copilot]

The build-summary job unconditionally depends on build-cpp, but build-cpp only runs conditionally (when build_cpp == 'true'). This will cause the summary job to be skipped when C++ builds are not triggered. Use if: always() on individual jobs or make the dependency conditional.

Suggested change

	needs: [determine-strategy, build-lite, build-full, build-cpp]
	needs: [determine-strategy, build-lite, build-full]