add a hello world algorithm.

CMakeLists.txt

+CMAKE_MINIMUM_REQUIRED(VERSION 3.0.0)
+
+find_package(GaudiProject)
+
+gaudi_project(cepc-offline HEAD
+              USE Gaudi v29r2 )
\ No newline at end of file

Examples/CMakeLists.txt

+
+gaudi_subdir(Examples v0r0)
+
+set(Examples_srcs
+    src/HelloWorld/*.cpp
+)
+
+gaudi_add_module(Examples ${Examples_srcs}
+    INCLUDE_DIRS GaudiKernel
+    LINK_LIBRARIES GaudiKernel
+)
\ No newline at end of file

Examples/src/HelloWorld/HelloAlg.cpp

+#include "HelloAlg.h"
+
+DECLARE_COMPONENT(HelloAlg)
+
+HelloAlg::HelloAlg(const std::string& name, ISvcLocator* pSvcLocator)
+: Algorithm(name, pSvcLocator) {
+
+}
+
+StatusCode
+HelloAlg::initialize() {
+    StatusCode sc;
+
+    info() << "MyInt: " << m_int.value() << endmsg;
+
+    return sc;
+}
+
+StatusCode
+HelloAlg::execute() {
+    StatusCode sc;
+    return sc;
+}
+
+StatusCode
+HelloAlg::finalize() {
+    StatusCode sc;
+    return sc;
+}
+
+

Examples/src/HelloWorld/HelloAlg.h

+#ifndef HelloAlg_h
+#define HelloAlg_h
+
+#include <GaudiKernel/Algorithm.h>
+#include "GaudiKernel/Property.h"
+
+class HelloAlg: public Algorithm {
+public:
+    HelloAlg(const std::string& name, ISvcLocator* pSvcLocator);
+
+    StatusCode initialize() override;
+    StatusCode execute() override;
+    StatusCode finalize() override;
+
+private:
+
+    Gaudi::Property<int> m_int{this, "MyInt", 42};
+};
+
+
+#endif

Generator/CMakeLists.txt

+
+gaudi_subdir(Generator v0r0)
\ No newline at end of file

README.md

 # cepc-offline
 
-CEPC offline software prototype
+CEPC offline software prototype based on Gaudi
 
 ## Packages
 
 * Core: Core Software Based on Gaudi
 
-* Simulation: Physics Generator & Detector Simulation
+* Generator: Physics Generator
 
-* Reconstruction
+* Simulation: Detector Simulation
 
-* Examples: For new comers
+* Reconstruction: Reconstruction
+
+* Examples: For new comers and users
+
+* cepcenv: tools to help developers build packages
 
-* cepcenv: tools to help developers build packages
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