论一位程序员从初级到高级再到高管晋升过程中的代码演进之路，其中，有你的影子吗？

一位 Go 程序员的进化史

初级 Go 程序员

package fac
func Factorial(n int) int {
 res := 1
for i := 1; i <= n; i++ {
 res *= i
 }
return res
}

学会使用函数的 Go 程序员

package fac
func Factorial(n int) int {
if n == 0 {
return 1
 } else {
return Factorial(n - 1) * n
 }
}

泛型 Go 程序员

package fac
func Factorial(n interface{}) interface{} {
 v, valid := n.(int)
if !valid {
return 0
 }
 res := 1
for i := 1; i <= v; i++ {
 res *= i
 }
return res
}

学会了多线程优化的 Go 程序员

package fac
import "sync"
func Factorial(n int) int {
var (
 left, right = 1, 1
 wg sync.WaitGroup
 )
 wg.Add(2)
 pivot := n / 2
go func() {
for i := 1; i < pivot; i++ {
 left *= i
 }
 wg.Done()
 }()
go func() {
for i := pivot; i <= n; i++ {
 right *= i
 }
 wg.Done()
 }()
 wg.Wait()
return left * right
}

掌握了 Go 设计模式的程序员

package fac
func Factorial(n int) <-chan int {
 ch := make(chan int)
go func() {
 prev := 1
for i := 1; i <= n; i++ {
 v := prev * i
 ch <- v
 prev = v
 }
close(ch)
 }()
return ch
}

学会使用成熟的解决方案修复 Go 语言缺点的程序员

package fac
/**
 * @see 
 */
type IFactorial interface {
 CalculateFactorial() int
}
// FactorialImpl implements IFactorial.
var _ IFactorial = (*FactorialImpl)(nil)
/**
 * Used to find factorial of the n.
 */
type FactorialImpl struct {
/**
 * The n.
 */
 n int
}
/**
 * Constructor of the FactorialImpl.
 *
 * @param n the n.
 */
func NewFactorial(n int) *FactorialImpl {
return &FactorialImpl{
 n: n,
 }
}
/**
 * Gets the n to use in factorial function.
 *
 * @return int.
 */
func (this *FactorialImpl) GetN() int {
return this.n
}
/**
 * Sets the n to use in factorial function.
 *
 * @param n the n.
 * @return void.
 */
func (this *FactorialImpl) SetN(n int) {
this.n = n
}
/**
 * Returns factorial of the n.
 *
 * @todo remove "if" statement. Maybe we should use a factory or somthing?
 *
 * @return int.
 */
func (this *FactorialImpl) CalculateFactorial() int {
if this.n == 0 {
return 1
 }
 n := this.n
this.n = this.n - 1
return this.CalculateFactorial() * n
}

高级 Go 程序员

package fac
// Factorial returns n!.
func Factorial(n int) int {
 res := 1
for i := 1; i <= n; i++ {
 res *= i
 }
return res
}

Go 语言之父 Rob Pike

package fac
// Factorial returns n!.
func Factorial(n int) int {
 res := 1
for i := 1; i <= n; i++ {
 res *= i
 }
return res
}

一个程序员的进化史

初中/高中时初入门

 10 PRINT "HELLO WORLD"
20 END

大一

 program Hello(input, output)
 begin
 writeln('Hello World')
end.

大四

 (defun hello
 (print
 (cons 'Hello (list 'World))))

初入职场

 #include <stdio.h>
void main(void)
{
char *message[] = {"Hello ", "World"};
int i;
for(i = 0; i < 2; ++i)
printf("%s", message[i]);
printf("\n");
 }

中级专家

 #include <iostream.h>
#include <string.h>
class string
 {
private:
int size;
char *ptr;
string() : size(0), ptr(new char[1]) { ptr[0] = 0; }
string(const string &s) : size(s.size)
 {
 ptr = new char[size + 1];
strcpy(ptr, s.ptr);
 }
 ~string()
 {
delete [] ptr;
 }
friend ostream &operator <<(ostream &, const string &);
string &operator=(const char *);
 };
 ostream &operator<<(ostream &stream, const string &s)
 {
return(stream << s.ptr);
 }
string &string::operator=(const char *chrs)
 {
if (this != &chrs)
 {
delete [] ptr;
 size = strlen(chrs);
 ptr = new char[size + 1];
strcpy(ptr, chrs);
 }
return(*this);
 }
int main()
{
string str;
 str = "Hello World";
cout << str << endl;
return(0);
 }

主程序员

 [
 uuid(2573F8F4-CFEE-101A-9A9F-00AA00342820)
 ]
 library LHello
 {
// bring in the master library
 importlib("actimp.tlb");
 importlib("actexp.tlb");
// bring in my interfaces
#include "pshlo.idl"
 [
 uuid(2573F8F5-CFEE-101A-9A9F-00AA00342820)
 ]
 cotype THello
 {
 interface IHello;
 interface IPersistFile;
 };
 };
 [
 exe,
 uuid(2573F890-CFEE-101A-9A9F-00AA00342820)
 ]
 module CHelloLib
 {
// some code related header files
 importheader(<windows.h>);
 importheader(<ole2.h>);
 importheader(<except.hxx>);
 importheader("pshlo.h");
 importheader("shlo.hxx");
 importheader("mycls.hxx");
// needed typelibs
 importlib("actimp.tlb");
 importlib("actexp.tlb");
 importlib("thlo.tlb");
 [
 uuid(2573F891-CFEE-101A-9A9F-00AA00342820),
 aggregatable
 ]
 coclass CHello
 {
 cotype THello;
 };
 };
#include "ipfix.hxx"
 extern HANDLE hEvent;
 class CHello : public CHelloBase
 {
 public:
 IPFIX(CLSID_CHello);
 CHello(IUnknown *pUnk);
 ~CHello();
 HRESULT __stdcall PrintSz(LPWSTR pwszString);
 private:
 static int cObjRef;
 };
#include <windows.h>
#include <ole2.h>
#include <stdio.h>
#include <stdlib.h>
#include "thlo.h"
#include "pshlo.h"
#include "shlo.hxx"
#include "mycls.hxx"
int CHello::cObjRef = 0;
 CHello::CHello(IUnknown *pUnk) : CHelloBase(pUnk)
 {
 cObjRef++;
return;
 }
 HRESULT __stdcall CHello::PrintSz(LPWSTR pwszString)
 {
printf("%ws
", pwszString);
return(ResultFromScode(S_OK));
 }
 CHello::~CHello(void)
 {
// when the object count goes to zero, stop the server
 cObjRef--;
if( cObjRef == 0 )
 PulseEvent(hEvent);
return;
 }
#include <windows.h>
#include <ole2.h>
#include "pshlo.h"
#include "shlo.hxx"
#include "mycls.hxx"
 HANDLE hEvent;
int _cdecl main(
int argc,
 char * argv[]
 ) {
 ULONG ulRef;
 DWORD dwRegistration;
 CHelloCF *pCF = new CHelloCF();
 hEvent = CreateEvent(, FALSE, FALSE, );
// Initialize the OLE libraries
 CoInitializeEx(, COINIT_MULTITHREADED);
 CoRegisterClassObject(CLSID_CHello, pCF, CLSCTX_LOCAL_SERVER,
 REGCLS_MULTIPLEUSE, &dwRegistration);
// wait on an event to stop
 WaitForSingleObject(hEvent, INFINITE);
// revoke and release the class object
 CoRevokeClassObject(dwRegistration);
 ulRef = pCF->Release();
// Tell OLE we are going away.
 CoUninitialize();
return(0); }
 extern CLSID CLSID_CHello;
 extern UUID LIBID_CHelloLib;
 CLSID CLSID_CHello = { /* 2573F891-CFEE-101A-9A9F-00AA00342820 */
0x2573F891,
0xCFEE,
0x101A,
 { 0x9A, 0x9F, 0x00, 0xAA, 0x00, 0x34, 0x28, 0x20 }
 };
 UUID LIBID_CHelloLib = { /* 2573F890-CFEE-101A-9A9F-00AA00342820 */
0x2573F890,
0xCFEE,
0x101A,
 { 0x9A, 0x9F, 0x00, 0xAA, 0x00, 0x34, 0x28, 0x20 }
 };
#include <windows.h>
#include <ole2.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "pshlo.h"
#include "shlo.hxx"
#include "clsid.h"
int _cdecl main(
int argc,
 char * argv[]
 ) {
 HRESULT hRslt;
 IHello *pHello;
 ULONG ulCnt;
 IMoniker * pmk;
 WCHAR wcsT[_MAX_PATH];
 WCHAR wcsPath[2 * _MAX_PATH];
// get object path
 wcsPath[0] = '\0';
 wcsT[0] = '\0';
if( argc > 1) {
 mbstowcs(wcsPath, argv[1], strlen(argv[1]) + 1);
 wcsupr(wcsPath);
 }
else {
 fprintf(stderr, "Object path must be specified\n");
return(1);
 }
 // get print string
if(argc > 2)
 mbstowcs(wcsT, argv[2], strlen(argv[2]) + 1);
else
 wcscpy(wcsT, L"Hello World");
printf("Linking to object %ws\n", wcsPath);
printf("Text String %ws\n", wcsT);
// Initialize the OLE libraries
 hRslt = CoInitializeEx(, COINIT_MULTITHREADED);
if(SUCCEEDED(hRslt)) {
 hRslt = CreateFileMoniker(wcsPath, &pmk);
if(SUCCEEDED(hRslt))
 hRslt = BindMoniker(pmk, 0, IID_IHello, (void **)&pHello);
if(SUCCEEDED(hRslt)) {
// print a string out
 pHello->PrintSz(wcsT);
 Sleep(2000);
 ulCnt = pHello->Release();
 }
else
printf("Failure to connect, status: %lx", hRslt);
// Tell OLE we are going away.
 CoUninitialize();
 }
return(0);
 }

初级黑客

 #!/usr/local/bin/perl
 $msg="Hello, world.\n";
if ($#ARGV >= 0) {
while(defined($arg=shift(@ARGV))) {
 $outfilename = $arg;
open(FILE, ">" . $outfilename) || die "Can't write $arg: $!\n";
print (FILE $msg);
close(FILE) || die "Can't close $arg: $!\n";
 }
 } else {
print ($msg);
 }
1;

中级黑客

 #include <stdio.h>
#define S "Hello, World\n"
 main(){exit(printf(S) == strlen(S) ? 0 : 1);}

资深黑客

 % cc -o a.out ~/src/misc/hw/hw.c
 % a.out

大师级黑客

 % echo "Hello, world."

初级经理

 10 PRINT "HELLO WORLD"
20 END

中级经理

 mail -s "Hello, world." bob@b12
 Bob, could you please write me a program that prints "Hello, world."?
 I need it by tomorrow.
 ^D

高级经理

 % zmail jim
 I need a "Hello, world." program by this afternoon.

高管

 % letter
 letter: Command not found.
 % mail
 To: ^X ^F ^C
 % help mail
 help: Command not found.
 % damn!
 !: Event unrecognized
 % logout

原文地址：

4月23日晚8点，欢迎来到CSDN直播间，与资深行业专家雷明老师一起探讨机器学习所必须掌握的数学知识。

为了写论文给 Linux “投毒”，导致整个大学都被 Linux 拉黑！