以下在x-y坐标系统上进行的游戏属于二维的随机行走。从原点（0，0）开始，每次迭代都是由向左，向上，向右或向下一个单位的随机不构成。当行动者返回原点时，行走结束。在二维世界这种情况发生的概率为1，而三维世界的概率小于1。请编写一个进行100次独立随机行走程序，并计算每个方向的步数的平均数。-The following on the xy coordinate system of the game is a two-dimensional random walk. From the origin (0,0), at each iteration are made to the left, up, right or down does not constitute a unit random. When actors return to the origin when walking over. In the two-dimensional world, the probability of this happening is 1, and the probability is less than a three-dimensional world. Please write a 100 times independent random walk process, and calculate the number of steps in each direction of the average.