有0，1，2三个数，此后，每次取出较大的两个数，用这两个数的和替换原先三个数中的任意一个。求需要使用最少的操作次数得到一个数x。-0, 1, 2 or three, Since then, every time you remove the larger of the two, with two numbers and replace any one of the original three numbers. Requirements need to use the minimum opera