ACSL "What Does This Program Do" Interpreter

Demo

Interpreter for the pseudocode used in American Computer Science League competitions in contest 1.

Features

These are the full capabilities of the language as defined by the ACSL wiki

Construct	Code Segment
Operators	! (not), ^ or ↑(exponent), *, / (real division), % (modulus), +, -, >, <, >=, <=, !=, ==, && (and), || (or) in that order of precedence
Functions	abs(x) - absolute value, sqrt(x) - square root, int(x) - greatest integer <= x
Variables	Start with a letter, only letters and digits
Sequential statements	INPUT variable variable = expression (assignment) OUTPUT variable
Decision statements	IF boolean expression THEN Statement(s) ELSE (optional) Statement(s) END IF
Indefinite Loop statements	WHILE boolean expression Statement(s) END WHILE
Definite Loop statements	FOR variable = start TO end STEP increment Statement(s) NEXT
Arrays:	1 dimensional arrays use a single subscript such as A(5). 2 dimensional arrays use (row, col) order such as A(2,3). Arrays can start at location 0 for 1 dimensional arrays and location (0,0) for 2 dimensional arrays. Most ACSL past problems start with either A(1) or A(1,1). The size of the array will usually be specified in the problem statement.
Strings:	Basically python strings

And here's more features found in practice problems that they failed to mention in their wiki:

Construct	Code Segment
Alternate Decision Statement Syntax	IF expression THEN Statement ELSE Statement (one line)
Program Early Termination	END

Example Code Snippets

input H, R
B = 0
if H>48 then
    B = B + (H - 48) * 2 * R
    H = 48
end if
if H>40 then
   B = B + (H - 40) * (3/2) * R
   H = 40
end if
B = B + H * R
output B

A = "BANANAS"
NUM = 0: T = ""
for J = len(A) - 1 to 0 step -1
     T = T + A[j]
next 
for J = 0 to len(A) - 1
    if A[J] == T[J] then NUM = NUM + 1
next

A(0) = 12: A(1) = 41: A(2) = 52
A(3) = 57: A(4) = 77: A(5) = -100
B(0) = 17: B(1) = 34: B(20) = 81
J = 0: K = 0: N = 0
while A(J) > 0
  while B(K) <= A(J)
    C(N) = B(K)
    N = N + 1
    k = k + 1
  end while
  C(N) = A(J): N = N + 1: J = J + 1
end while
C(N) = B(K)