2018-05-optimised

DEFLNG A-Z
DIM b(50000) AS _BYTE, s(50000&) AS _BYTE
DIM m AS DOUBLE: m = TIMER(0.0001)
OPEN "input05.txt" FOR BINARY AS #1
GET #1, , b()
CLOSE #1

FOR i = 0& TO 49999&
  IF (s(p) XOR b(i) XOR 32&) THEN p = p + 1&: s(p) = b(i) ELSE p = p - 1&
NEXT
PRINT "Part 1:"; p

best = p: p1 = p

FOR c = 97& TO 122&: p = 0&
  FOR i = 1& TO p1
    IF (s(i) OR 32&) XOR c THEN
      IF (b(p) XOR s(i) XOR 32&) THEN p = p + 1&: b(p) = s(i) ELSE p = p - 1&
    END IF
  NEXT
  IF p < best THEN best = p
NEXT
PRINT "Part 2:"; best
PRINT "time"; (TIMER(0.0001) - m) * 1000; "ms"