essentially same code,but different result

This is UCB CS61A’s firt project hog ‘s problem5

this is wrong code(my code)

while(score0<goal and score1<goal):
    if who==0 :
        cur_strategy = strategy0
        cur_score = score0
        cur_op_score=score1
        cur_op_strategy = strategy1
    else:
        cur_strategy = strategy1
        cur_score = score1
        cur_op_score=score0
        cur_op_strategy = strategy0
    cur_score=cur_score+take_turn(cur_strategy(cur_score,cur_op_score),cur_op_score,dice)

    if(extra_turn(cur_score,cur_op_score)==False):
        who=other(who)

this is the correct code(I have tested it)

while score0 < goal and score1 < goal:
        if who == 0:
            num_rolls = strategy0(score0, score1)
            score0 += take_turn(num_rolls, score1, dice)
            who = other(who) if extra_turn(score0, score1) == False else who
        else:
            num_rolls = strategy1(score1, score0)
            score1 += take_turn(num_rolls, score0, dice)
            who = other(who) if extra_turn(score1, score0) == False else who

But actually,I think these two codes are essentially same.

I don’t know whether this is the problem (the quote from the project)

Only call a strategy function once per turn (or risk breaking the GUI).

>Solution :

I think that comes from the fact that in order to update the score0 an score1 variables, you define cur_score and update it instead. The problem is that cur_score is only a copy of the score you want to update, it is not the same object.