Babaza Game

def bestStep(start: str, goal: str):
    print(start)
    if start != goal:
        oneMove = True
        for i in range(0,len(start)-1):
            oneMove = oneMove and (start[i] == goal[i] or start[i+1] == goal[i+1])
        if oneMove:
            return bestStep(goal,goal)
        mustGoNext = [False for i in range(0,len(start))]
        for i in range(0,len(start)-1):
            mustGoNext[i+1] = mustGoNext[i+1] or (start[i+1] == goal[i])
            mustGoNext[i] = mustGoNext[i] or (start[i] == goal[i+1])
        for x in range(0,len(start)):
            for i in range(0,len(start)):
                if i+2 < len(start):
                    mustGoNext[i] = mustGoNext[i] or ((start[i] != goal[i]) and mustGoNext[i+2])
                if i-2 >= 0:
                    mustGoNext[i] = mustGoNext[i] or ((start[i] != goal[i]) and  mustGoNext[i-2])
        for i in range(1,len(start)-1):
            mustGoNext[i] = mustGoNext[i] or ((start[i] != goal[i]) and not mustGoNext[i-1] and not mustGoNext[i+1])
        mustGoNext[len(start)-1] = mustGoNext[len(start)-1] or ((start[len(start)-1] != goal[len(start)-1]) and not mustGoNext[len(start)-2])
        twoMove = True
        for i in range(0,len(start)-1):
            twoMove = twoMove and not (mustGoNext[i] and mustGoNext[i+1])
        free = list(set(list(map(chr, range(ord('A'), ord('Z')+1)))).difference(set(list(start)).union(set(list(goal)))))[0]
        if twoMove:
            def helper(i):
                if mustGoNext[i]: 
                    return goal[i] 
                else: 
                    return start[i]
            
            return bestStep(''.join([helper(i) for i in range(0,len(start))]),goal)
        def helper2(i):
            if ((i%2) == 1): 
                return free 
            else: 
                return start[i]
        return bestStep(''.join([helper2(i) for i in range(0,len(start))]),goal)
                
                

bestStep(input(),input())

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED