Засіб, який дозволяє введення даних, що відповідають визначеним умовам.​

Выполняя алгоритм, получаем следующий результат (15 итераций)

1. 0..65534 -> 32767
2. 0..32766 -> 16383
3. 0..16382 -> 8191
4. 0..8190  -> 4095
5. 0..4094  -> 2047
6. 2048..4094 -> 3071
7. 2048..3070 -> 2559
8. 2560..3070 -> 2815
9. 2816..3070 -> 2943
10. 2944..3070 -> 3007
11. 2944..3006 -> 2975
12. 2976..3006 -> 2991
13. 2992..3006 -> 2999
14. 3000..3006 -> 3003
15. 3000..3002 -> 3001

Если лень перебирать вручную, можно воспользоваться программой

var k,l,r,x,f:integer;
begin
f := 3001;
l := 0;
r := 65534;
x := (l + r) div 2;
k := 1;
while (x <> f) and (l < r) do
  begin
  writeln(k,' ',l,' ',r,' ',x);
  k := k + 1;
  if f < x then r := x - 1
    else l := x + 1;
  x := (l + r) div 2
  end;
writeln(k,' ',l,' ',r,' ',x);
end.

#include

#include

#include

#include

#include

#include

typedef struct

{

char imya[40];

char familiya[40];

char otchestvo[40];

int telefon;

int texpasport;

float pages ;

}gor;

void form(char mass[10], char *imya, char *familiya, char *otchestvo, int telefon, int texpasport)

{

file *f;

gor y;

int i;

if ((f=fopen(mass,"w"))==null) exit(1);

for (i=1; i< =3; i++)

{

cout< < "vvedite imya: ";

cin> > imya;

cout< < "vvedite familiya: ";

cin> > familiya;

cout< < "vvedite otchestvo: ";

cin> > otchestvo;

cout< < "vvedite telefon: ";

cin> > telefon;

cout< < "vvedite texpasport: ";

cin> > texpasport;

fwrite(& y,sizeof(gor),1,f);

if(ferror(f)! =null)

exit(2);

}

fclose(f);

}

void vivod(char mass[50])

{

file *f;

gor z;

if ((f=fopen(mass, "r"))==null) exit(3);

cout< < "fail: "<

while (! feof(f)) {

fread (& z,sizeof(gor),1,f);

if (! feof(f))

{

cout< < "imya: "<

cout< < "familiya: "<

cout< < "otchestvo: "<

cout< < "telefon: "<

cout< < "texpasport: "<

}

fclose(f);

}

}

void del(char fo[10], char fi[10])

{

file *f1,*f2;

gor d;

//char temp[40];

if ((f1=fopen(fi,"r"))==null) exit(4);

if ((f2=fopen(fo,"w"))==null) exit(5);

//cout < < "vvedite nazvanie na ydalenie - ";

//cin > > temp;

for (int i=0; i< 3; i++)

{

fread(& d,sizeof(gor),1,f1);

if (feof(f1)) break;

if (i> 2)

fwrite (& d,sizeof(gor),1,f2);

}

fclose(f2);

fclose(f1);

}

void dobav(char fi[10], char fo[10],char *imya, char *familiya, char *otchestvo, int telefon, int texpasport)

{

int q;

int i;

gor d;

file *f1,*f2;

char temp[40];

if ((f1=fopen(fi, "r"))==null) exit(4);

if ((f2=fopen(fo,"r+"))==null) exit(5);

cout < < "vvedite familiu, pered kotorym nuzno dobavit element: ";

cin > > temp;

for (i=0; i< 10; i++)

{

fread(& d,sizeof(gor),1,f2);

if (feof(f2)) break;

if (strcmp(d.familiya, temp)) break;

q=i;

}

for (i=0; i< 10; i++)

{

if (feof(f2)) break;

fwrite (& d,sizeof(gor),1,f2);

if (i==q-1)

{

cout< < "vvedite imya: ";

cin> > imya;

cout< < "vvedite familiya: ";

cin> > familiya;

cout< < "vvedite otchestvo: ";

cin> > otchestvo;

cout< < "vvedite telefon: ";

cin> > telefon;

cout< < "vvedite texpasport: ";

cin> > texpasport;

cout <

}

}

fclose(f2);

fclose(f1);

}

void main()

{

int n=10;

//cout < < "vvedite kol-vo zapisey: - ";

//cin> > n;

//cout <

form("f1.txt",n);

vivod("f1.txt");

del("f1.txt","f2.txt");

cout < < "posle udalenia: \n";

vivod("f2.txt");

getch();

n=1;

system("cls");

dobav ("f2.txt","f2.txt");

cout < < "posle dobavlenia: \n";

vivod ("f2.txt");

getch();

}