''' This program is a bf interpreter. It takes code written in bf and executes it. bf, short for brainfuck, is an extremely difficult to use (but still Turing complete) esoteric programming language. In bf, the computers memory is conceptualized as a tape divided into cells, each of which stores a number. The tape is kind of like a list or a one dimensional array. A variable call the pointer is used to store the index of the cell currently being read. You could think of it as being like an arrow pointing to a cell on the tape. By changing the number in the pointer, we can change which cell is being read/pointed to. > Is to increment the pointer (Causing it to read the cell One space to the right). < Is to decrement the pointer (Causing it to read the cell one space to the left). + Is the command to increment the number in the cell being pointed to. - Is the command to decrement the number in the cell being pointed to. . prints the character who's ASCII value equals number in the cell being pointed to. , Takes a user input and stores it in the cell being pointed to. [ means if the cell being pointed to == 0: Goto The matching ] ] means if the cell being pointed to != 0: Goto The matching [ basically, [code in brackets] means while cell_being_pointed_to != 0: code in brackets Any other characters will be ignored and can be used as comment example: input: ++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++. output: Hello World! ''' # Write your bf program here a = '++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.' def bracket_parse(x): point = 0 stac = [] b = [] while point < len(a): if a[point] is '[': stac.append(point) point += 1 elif a[point] is ']': c = (stac[-1], point) b.append(c) stac = stac[:-1] point += 1 else: point += 1 return b def interpret(x): d = bracket_parse(a) tp = [0 for i in range(len(x)-1)] cell_pnt = 0 ins_pnt = -1 output = '' while ins_pnt < len(tp): ins_pnt += 1 if x[ins_pnt] is '+': tp[cell_pnt] += 1 continue elif x[ins_pnt] is '-': tp[cell_pnt] -= 1 continue elif x[ins_pnt] is '>': cell_pnt += 1 continue elif x[ins_pnt] is '<': cell_pnt -= 1 continue elif x[ins_pnt] is '[': for i in d: if i[0] == ins_pnt and tp[cell_pnt] == 0: ins_pnt = i[1] continue else: continue elif x[ins_pnt] is ']': for i in d: if i[1] == ins_pnt and tp[cell_pnt] != 0: ins_pnt = i[0] continue else: continue elif x[ins_pnt] is '.': output = output + chr(tp[cell_pnt]) continue elif x[ins_pnt] is ',': tp[cell_pnt] = int(input()) continue else: continue return output print(interpret(a))

(not done) bf