Лабораторная работа1 / FORMLAGR

program FormLagr;

const
Nmax = 50;

type
massiv = array[0..Nmax] of real;

var
X,Y,D: massiv;
P,x0: Real;
i,j,n: Integer;
exit:String;

function Lagr(x0:real):Real;
var
s:real;
begin
s:=0;
for i:=0 to n do
s:=s+Y[i]/((x0-X[i])*D[i]+0);
lagr:=P*s;
end;

begin
Write('n= ');
ReadLn(n);
for i:=0 to n do begin
Write('x',i,'= ');
ReadLn(X[i]);
Write('y',i,'= ');
ReadLn(Y[i]);
end;
{D}
for i:=0 to n do begin
D[i]:=1;
for j:=0 to n do
if j<>i then
D[i]:=D[i]*(X[i]-X[j]);
end; {D}
repeat
Write('x= ');
ReadLn(x0);
{P}
P:=1;
for i:=0 to n do
P:=P*(x0-X[i]); {P}
WriteLn('y= ',lagr(x0):3:3);
until false;
end.