27 lines
425 B
ObjectPascal
27 lines
425 B
ObjectPascal
var
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n,i:integer;
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r,x1,x2,x3,y1,y2,y3,per:real;
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f:Text;
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begin
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Assign(f, 'input.txt');
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Reset(f);
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Read(f, n);
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read(f, r);
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Read(f, x1, y1);
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x3:=x1;
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y3:=y1;
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per:=0;
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for i:=0 to n-2 do begin
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Read(f, x2, y2);
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per:=per + Sqrt(Sqr(x2-x1)+Sqr(y2-y1));
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x1:=x2; y1:=y2;
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end;
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per:=per+Sqrt(Sqr(x1-x3)+Sqr(y1-y3)+Sqr(x2-x1)+Sqr(y2-y1));
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per:=per+((2*Pi*r)/4)*n;
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Close(f);
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Rewrite(f, 'output.txt');
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write(f, per:0:2);
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Close(f);
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end.
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