求大神分析这段代码

void init(char plate[N+2][N+2], char ***snake_x, int *len) //初始化
{
int i, j;
char **snake = NULL;
*len = 3;
score[0] = score[3] =3;
snake = (char **)realloc(snake, sizeof(char *) * (*len));
for (i = 0; i < *len; ++i)
snake[i] = (char *)malloc(sizeof(char) * 2);
for (i = 0; i < 3; ++i)
{
snake[i][0] = N/2 + 1;
snake[i][1] = N/2 + 1 + i;
}
for (i = 1; i <= N; ++i)
for (j = 1; j <= N; ++j)
plate[i][j] = 1;
apple[0] = rand()%N + 1; apple[1] = rand()%N + 1;
apple[2] = 1;
for (i = 0; i < N + 2; ++i)
{
gotoxy(0, i);
for (j = 0; j < N + 2; ++j)
{
switch (plate[i][j])
{
case 0:color(11);printf("■");color(11); continue;
case 1: printf(" "); continue;
default: ;
}
}
putchar('\n');
}
for (i = 0; i < (*len); ++i)
{
gotoxy(snake[i][1] * 2, snake[i][0]);
printf("■");
}
putchar('\n');
*snake_x = snake;
}