program Iteraz;
uses graph,crt;
var
a,b,x1,x,f1,f2,e:real;
i,n:integer;

function ArcSin ( X : Real ): Real;
begin
if X = 1.0 then { чтобы не было деления на 0 }
ArcSin := Pi / 2.0
else
ArcSin := ArcTan ( X / Sqrt ( 1 - X * X ) );
end;

function f(tmpX:real):real;
begin
f:=sqrt(1*tmpX*tmpX)-ArcSin(tmpX);
end;

begin
a:=0;
b:=0.99;
x1:=a;
f1:=f(x1);
e:=0.001;
n:=round((b-a)/e);
writeln('Metod iterazii');
for i:=1 to n do begin
x:=x1+(b-a)/n;
f2:=f(x);
if f1*f2<=0 then begin
writeln('Done. X = ',(X+x1)/2:6:4);
writeln('Kolichectvo iterazii = ',i);
end;
x1:=x;f1:=f2;
end;

readkey;
end.

program ITERAT;
uses crt;

const max_iter=100;   {максимальное количество итераций}

var
 i :integer;
 x,x0,eps,M:real;

function ArcSin ( X : Real ): Real;
begin
if X = 1.0 then { чтобы не было деления на 0 }
ArcSin := Pi / 2.0
else
ArcSin := ArcTan ( X / Sqrt ( 1 - X * X ) );
end;


function F(tmpX:real):real; {функция}
 begin
   f:=sqrt(1*tmpX*tmpX)-ArcSin(tmpX);
 end;

begin {основная программа}
clrscr;
x:=0;
x0:=0.99;
eps:=0.001;

 i:=0;
 repeat
   M:=-(F(x+eps)-F(x-eps))/(2*eps); {коэффициент для улучшения сходимости}
   x0:=x;
   x:=x0+F(x0)/M; {сердце метода итераций}
   inc(i);
 until (abs(x-x0)<=eps)or(i>max_iter);

 if (abs(x-x0)<=eps) then writeln('Otvet: X= ',x:6:4,' naiden za ',i,' shagov')
 else writeln('Otvet ne naiden! Za ',max_iter:0,' shagov.');

readkey;
end.

program SREDNEE_GEOMETRICHESKOE;

var
SrGeoM:real;
i:integer;

begin
SrGeom:=1;
for i:=1 to 9 do SrGeom:=SrGeom*i;
srGeom:=exp(ln(srGeom)/i);
writeln('Srednee geometricheskoe vseh zelih polozhitelnix chisel menshe 10 [1..9] = ',SrGeom:6:4);

readln;
end.

Srednee geometricheskoe vseh zelih polozhitelnix chisel menshe 10 [1..9] = 4.147
2

Console.WriteLine("Enter x: ");
int x = int.Parse(Console.ReadLine());
Console.WriteLine("Enter y: ");
int y = int.Parse(Console.ReadLine());
Console.WriteLine("Enter a: ");
char a = char.Parse(Console.ReadLine());
int F = 0;
if(Char.IsDigit(a))
	{
		F = x > y ? y : x;
	}
else if(Char.IsLetter(a))
	{
		F = x > y ? x : y;
	}
Console.WriteLine("\nX: {0} ; Y: {1} ; A: {2}\nF: {3}", x,y,a,F);
Console.ReadLine();

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ABONENTS_COUNT_MAX 500
#define LINE_MAX 256

typedef struct {
	char name[LINE_MAX];
	char phone_number[LINE_MAX];
	unsigned int installation_year; 
} abonent;

int abonents_compare (const void * a, const void * b) {
  return strcmp(((abonent*)a)->name,((abonent*)b)->name);
}

int main(int argc, char** argv){

	FILE * text_file = fopen(argv[1],"rt");
    
    abonent abonents[ABONENTS_COUNT_MAX];
    
    int abonents_count = 0;
    
    char buf_name[LINE_MAX], buf_number[LINE_MAX];
    
    int buf_year;
    
	while( fscanf(text_file,"%s %s %d", buf_name,buf_number,&buf_year)!= EOF){
		strcpy(abonents[abonents_count].name,buf_name);
		strcpy(abonents[abonents_count].phone_number,buf_number);
		abonents[abonents_count++].installation_year = buf_year;
	}
	
	fclose(text_file);
	
   qsort (abonents, abonents_count, sizeof(abonent), abonents_compare);
   FILE * struct_file = fopen("base.txt","w");	
   fwrite(abonents,sizeof(abonent),abonents_count,struct_file);
   fclose(struct_file);
	
	char name[LINE_MAX];
	while(1){
		printf("Enter the name: ");
		scanf("%s",name);
		for(int i=0; i<abonents_count; i++)
			if(strcmp(abonents[i].name,name)==0)
				printf("%s\n",abonents[i].phone_number);
  }
	
	return 0;
}