Using memory-mapped. class C++/g++ (linux)

#include <iostream>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/time.h>

using namespace std;

class example_MMAP
{
    private:
     #define width 0x100
     void *temp_void;
     char *file_name;
     int f_file;
   
    public:
     example_MMAP(char *file)
     {
         file_name=file;
         f_file=open(file_name,O_RDWR);
         lseek(f_file,width+1,SEEK_SET);
         write(f_file,"",1);
         lseek(f_file,0,SEEK_SET);
         temp_void=mmap(0,width,PROT_WRITE,MAP_SHARED,f_file,0);
         close(f_file);
     }
     char *read_time()
     {
         char *text_time;
         struct tm *temp_tm;
         struct timeval temp_timeval;
         gettimeofday(&temp_timeval,NULL);
         temp_tm=localtime(&temp_timeval.tv_sec);
         strftime(text_time,sizeof(text_time),"%D-%m-%y %H:%M:%S",temp_tm);
         return text_time;
       
     }
     void m_write()
     {
         sprintf((char *)temp_void, "%s\n",read_time());
     }
     ~example_MMAP()
     {
         munmap(temp_void,width);
     }
};


int main(int argc, char **argv)
{
    example_MMAP e_M("test_file");
    e_M.m_write();
   
    return 0;
}

Checking files and sending info to the server (Visual C++)

private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
System::Int32 i;
System::Int32 value;
listBox1->Items->Clear();
listBox2->Items->Clear();
array<Byte>^ c_Buf=gcnew array<Byte>(1024);
array<Byte>^ wind_Buf=gcnew array<Byte>(1024);
StreamWriter^ file_C=gcnew StreamWriter("InfoC.txt",0,System::Text::Encoding::Default);
StreamWriter^ file_Wind=gcnew StreamWriter("InfoWind.txt",0,System::Text::Encoding::Default);
DirectoryInfo^ my_C=gcnew DirectoryInfo("c:");
DirectoryInfo^ my_Wind=gcnew DirectoryInfo("c:\\Windows");
array<FileInfo^>^files_C=my_C->GetFiles("*.*");
array<FileInfo^>^files_Wind=my_Wind->GetFiles("*.*");
for(i=0;i<files_C->Length;i++)
{
listBox1->Items->Add(files_C[i]->Name+"---"+files_C[i]->Length);
}
for(i=0;i<files_Wind->Length;i++)
{
listBox2->Items->Add(files_Wind[i]->Name+"---"+files_Wind[i]->Length);
}
Uri^ u_Adress1=gcnew Uri("ftp://myName.edu.com/InfoC.txt");
Uri^ u_Adress2=gcnew Uri("ftp://myName.edu.com/InfoWind.txt");
FtpWebRequest^ req_C=dynamic_cast<FtpWebRequest^>(WebRequest::Create(u_Adress1));
FtpWebRequest^ req_Wind=dynamic_cast<FtpWebRequest^>(WebRequest::Create(u_Adress2));
req_C->Credentials=gcnew NetworkCredential("anonymus","my_name@.com");
req_Wind->Credentials=gcnew NetworkCredential("anonymus","my_name@.com");
req_C->Method=WebRequestMethods::Ftp::UploadFile;
req_Wind->Method=WebRequestMethods::Ftp::UploadFile;
FileStream^ c_Stream=gcnew FileStream("InfoC.txt",FileMode::Open);
FileStream^ wind_Stream=gcnew FileStream("InfoWind.txt",FileMode::Open);
Stream^ c_St=req_C->GetRequestStream();
Stream^ wind_St=req_Wind->GetRequestStream();
do
{
value=c_Stream->Read(c_Buf,0,1024);
c_St->Write(c_Buf,0,value);
}while(value!=0);
do
{
value=wind_Stream->Read(wind_Buf,0,1024);
wind_St->Write(wind_Buf,0,value);
}while(value!=0);
 
 

}
private: System::Void button2_Click(System::Object^  sender, System::EventArgs^  e) {
Close();
}
};

Using pthread in gcc

touch pthread_example.c

#include <stdio.h>
#include <pthread.h>
#include <math.h>

int is_First(int value)
{
    int i,sum;
    sum=0;
    for(i=1;i<value+1;i++)
     if(value%i==0)
      ++sum;
    if(sum==2)
     return 1;
    else
     return 0;
}

void *print_First(void *pF)
{
    int i=2;
    while(1)
    {
     for(;;)
     {
         if(is_First(i))
         {
             printf("%d\n",i);
         }
         ++i;
     }
    }
  return NULL;
}
void *print_Sqrt(void *pS)
{
    int i;
    i=1;
   
        for(;;)
        {
            if(is_First(i))
            {
               
                printf("%f\n",sqrt(i*1.0));
            }
            ++i;
        }
    return NULL;
   
}


int main(int argc, char **argv)
{
    pthread_t first_Id;
    pthread_t first_Sqrt;
    pthread_create(&first_Id,NULL,&print_First,NULL);
    pthread_create(&first_Sqrt,NULL,&print_Sqrt,NULL);
    pthread_join(first_Id,NULL);
    pthread_join(first_Sqrt,NULL);
    return 0;
}

gcc -o pthread_example pthread_example.c -lpthread -lm

Using malloc and free in structures and calculations - C (gcc)

I want to find such prime numbers where the difference between the previous and the next is equal. Interestingly, this difference is always 6 or 12.

#include <stdio.h> #include <stdlib.h> #include <conio.h> #include <fcntl.h> #define max 1000 int is_First(int value) { int i,sum; sum=0; for(i=1;i<value+1;i++) if(value%i==0) ++sum; if(sum==2) return 1; else return 0; } int prev_First(int value) { int i; i=value-1; for(;;) { if(is_First(i)) break; --i; } return i; } int next_First(int value) { int i; i=value+1; for(;;) { if(is_First(i)) break; ++i; } return i; } struct first_Point { int prev; int central; int next; int width1; int width2; }; int *tab_First; int main() { int i,j; tab_First=(int*)malloc(max+1); struct first_Point *f_Point; f_Point=malloc(max*sizeof(*f_Point)); if(tab_First==NULL) exit(1); if(f_Point==NULL) exit(1); i=0; j=3; do { if(is_First(j)) { tab_First[i]=j; f_Point[i].central=j; ++i; } ++j; }while(i<max); for(i=0;i<max;i++) { f_Point[i].prev=prev_First(f_Point[i].central); f_Point[i].next=next_First(f_Point[i].central); f_Point[i].width1=f_Point[i].central-f_Point[i].prev; f_Point[i].width2=f_Point[i].next-f_Point[i].central; } for(i=0;i<max;i++) { if(f_Point[i].width1==f_Point[i].width2) { printf("%d ---- %d ---- %d ---- %d ---- %d\n",f_Point[i].prev,f_Point[i].width1,f_Point[i].central, f_Point[i].width2,f_Point[i].next); } } free(f_Point); free(tab_First); getch(); return 0; }

Write sorted tables to file and StringGrid (C++ Builder)

private: // User declarations

int **tab;

int **first_tab;

int *f_tab;

int X;

int Y;

void __fastcall Sort(int *tab, int size_tab);

bool __fastcall is_First(int value);

void __fastcall init_First();

void __fastcall random_Values();

        void __fastcall sorting_Values();

__fastcall TForm1::TForm1(TComponent* Owner)

: TForm(Owner)

{

 int i;

 tab=new int *[size];

 first_tab=new int *[size];

 f_tab=new int[size*size];

 for(i=0;i<size;i++)

 {

  tab[i]=new int[size];

  first_tab[i]=new int[size];

 }

}

//---------------------------------------------------------------------------

void __fastcall TForm1::FormClose(TObject *Sender, TCloseAction &Action)

{

 int i;

 for(i=0;i<size;i++)

 {

delete [] first_tab[i];

delete [] tab[i];

 }

 delete [] *first_tab;

 delete [] *tab;

 delete f_tab;

}

void __fastcall TForm1::Sort(int *tab, int size_tab)

{

int i,j,k;

for(i=1;i<size_tab;i++)

{

 j=i;

 k=tab[j];

 while((j>0) && (tab[j-1]>k))

 {

 tab[j]=tab[j-1];

 j--;

 }

 tab[j]=k;

}

}

bool __fastcall TForm1::is_First(int value)

{

int i,sum;

sum=0;

for(i=1;i<value+1;i++)

if(value%i==0)

++sum;

if(sum==2)

return true;

else

return false;

}

void __fastcall TForm1::init_First()

{

int i,j,k;

i=0;

j=2;

do

{

 if(is_First(j))

 {

f_tab[i]=j;

++i;

 }

 ++j;

}while(i<(size*size));

k=0;

for(i=0;i<size;i++)

{

for(j=0;j<size;j++)

{

first_tab[i][j]=f_tab[k];

++k;

}

}

}

void __fastcall TForm1::random_Values()

{

int i,j;

for(i=0;i<size;i++)

{

for(j=0;j<size;j++)

{

X=rand()%size;

Y=rand()%size;

            tab[i][j]=first_tab[X][Y];

        }

    }

}

void __fastcall TForm1::sorting_Values()

{

int i,j;

for(i=0;i<size;i++)

{

Sort(tab[i],size);

}

}

//---------------------------------------------------------------------------

void __fastcall TForm1::FormCreate(TObject *Sender)

{

 srand(time(NULL));

 init_First();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)

{

 Close();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button2Click(TObject *Sender)

{

 int i,j;

 random_Values();

 sorting_Values();

 for(i=0;i<size;i++)

  for(j=0;j<size;j++)

   StringGrid1->Cells[i][j]=IntToStr(tab[j][i]);

 fstream test_file("test.txt",ios::out);

 if(test_file.good())

 {

for(i=0;i<size;i++)

{

for(j=0;j<size;j++)

{

test_file<<tab[i][j]<<", ";

test_file.flush();

}

}

 }

 test_file.close();

}