С++

Нужно переписать эту программу с паскаля на Си , Паскаль я не понимаю, помогите пожалуйста , плачу хорошо

program simp1; 

{ integration by Simpson's method }

const tol = 1.0E-6; 

var sum,upper,lower : real;

function fx(x: real): real; 

begin 

fx:=exp(-x/2) 

end; { function fx }

function dfx(x: real): real; 

begin 

dfx:=-(exp(-x/2))/2 

end; { function fx }

procedure simps(lower,upper,tol : real; var sum : real); 

{ numerical integration by Simpson's rule } 

{ function is fx, limits are lower and upper } 

{ with number of regions equal to pieces } 

{ partition is delta_x, answer is sum }

var i : integer; 

x,delta_x,even_sum, odd_sum,end_sum, end_cor,sum1 : real; 

pieces : integer;

begin 

pieces:=2; 

delta_x:=(upper-lower)/pieces; 

odd_sum:=fx(lower+delta_x); 

even_sum:=0.0; 

end_sum:=fx(lower)+fx(upper); 

end_cor:=dfx(lower)-dfx(upper); 

sum:=(end_sum+4.0*odd_sum)*delta_x/3.0; 

repeat 

pieces:=pieces*2; 

sum1:=sum; 

delta_x:=(upper-lower)/pieces; 

even_sum:=even_sum+odd_sum; 

odd_sum:=0.0; 

for i:=1 to pieces div 2 do 

begin 

x:=lower+delta_x*(2.0*i-1.0); 

odd_sum:=odd_sum+fx(x) 

end; 

sum:=(7.0*end_sum+14.0*even_sum+16.00*odd_sum 

+end_cor*delta_x)*delta_x/15.0; 

until (sum

end; { simps }

begin { main program } 

lower:=1.0; 

upper:=9.0; 

simps(lower,upper,tol,sum); 

writeln; 

writeln(chr(7),'area= ',sum) 

end.