Program in ALGOL

ALGOL 58 Program

// the main program, calculate the mean of
// some numbers 
begin
  integer N;
  Read Int(N);

  begin
    real array Data[1:N];
    real sum, avg;
    integer i;
    sum:=0;

    for i:=1 step 1 until N do
      begin real val;
        Read Real(val);
        Data[i]:=if val<0 then -val else val
      end;

    for i:=1 step 1 until N do
      sum:=sum   Data[i];
    avg:=sum/N;
    Print Real(avg)
  end
end    

ALGOL 60 Program

procedure problem (a, b);
   value a, b; integer a, b;
      begin integer k; real e;
         for k := 2 ´ (a Ö 2)   1 step 2 until b do
            begin
               e := if prime(k) then sqrt(3 ´ k   sin(k))
                                else sqrt(4 ´ k   cos(k));
               if prime(k) then putlist(k, e, 'prime')
                           else putlist(k, e, 'nonprime')
            end
      end problem;

ALGOL 68 Program

mode node = struct ( int val, ref node left, right); 
ref node nonode = nil; 
loc ref node start := nonode; 

proc insert = (int v, ref ref node place) ref node: 
if place :/=: nonode 
then if v < val of place then insert(v,left of place) 
else #v > val of place# insert(v, right of place) 
fi 
else place := heap node := (v, nonode, nonode) 
fi;