Program to convert an array of test grades (0-100) into "letter grades"
(0-4).

	program grades;
	type
		a300 = array[1..300] of integer;
	var
        	grade: a300;
		used: integer;
        	match, command: string;

	procedure figure(var score: a300; var limit:integer);
		var
			i: integer;
		begin
		i := 0;
		while i < limit  do
			begin
			i := i + 1;
			if y[i] >= 90 then
				begin
				y[i] := 4;
				end
			else
				begin
				if y[i] >= 80 then
					begin
					y[i] := 3;
					end
				else
					begin
					if y[i] >= 70 then
						begin
						y[i] := 2;
						end
					else
						begin
						if y[i] >= 60 then
							begin
							y[i] := 1;
							end
						else 
							begin
							y[i] := 0;
							end;
						end;
					end;
				end;
			end;
		end;
	
	begin
	
	{code to load data into grade and set used to tell how many values
	were entered.}
	
	figure(grade, used);
	
	{code to make use of the grades in grade}
	
	end.

Note:  In class we used a more compact form of the nested if/then/else
statements by omitting the begin/ends where there was only one statement
in the compand statement and by using a different indentation
scheme.  This format is often used for deeply nested if/then/else
structures like this.  (The alternative is to keep indenting until you
run off the right side of the page :-)  The more compact form is shown
below but is logically identical.

		if y[i] >= 90 then
			y[i] := 4
		else if y[i] >= 80 then
			y[i] := 3
		else if y[i] >= 70 then
			y[i] := 2
		else if y[i] >= 60 then
			y[i] := 1
		else 
			y[i] := 0;

Program with factorial procedure that uses recursion to calculate the
factorial:

	program recurse;
	var
   	i, j: integer;
	procedure fact(var n, f: integer);
    		var
			m, g: integer;
    		begin
    		writeln(' fact in: ', n); {debugging output}
    		if n <= 1 then
			begin
			f := 1;
			end
    		else
			begin
			m := n - 1;
			fact(m, g);
			f := n * g;
			end;
    		writeln(' fact out: ', f); {debugging output}
    		end;
	begin
	write('n? ');
	readln(i);
	fact(i, j);
	writeln(i:5, ' factorial is ',j:6);
	readln;
	end.

Note that the statements flagged with  {debugging output} would normally
not be included but are here to give some clues as to how it all works.

Sample output:

>n?
<4
> fact in: 4
> fact in: 3
> fact in: 2
> fact in: 1
> fact out: 1
> fact out: 2
> fact out: 6
>fact out: 24
>    4 factorial is     24