char *AllList(char *str, int *pNum)
{
    int i, j, k, n;
    int len = strlen(str);
    int Total = 0;
    int count, oldcount;
    int size;
    char *Buf;
    char *p, *p1;

    if (len > 10) return NULL;

    //计算总的组合数目
    for (i = 0, j = 1; i < len; i++)
    {
        j *= (len - i);
        Total += j;
    }

    //创建二维数组, 存放全部组合
    size = len + 1;
    if ((Buf = (char *)malloc(Total * size)) == NULL)
    {
        return NULL;
    }

    for (k = 0, count = 0; k < len; k++)  //所有要插入的字符
    {
        oldcount = count;
        p = Buf;
        p1 = Buf + count * size;
        for (i = 0; i < oldcount; i++, p += size)  //插入到所有字符串中,形成新的字符串
        {
            n = strlen(p);
            for (j = 0; j <= n; j++, count++, p1 += size) //在字符串所有位置插入
            {
                memcpy(p1, p, n);
                p1[n] = p1[j];
                p1[j] = str[k];
                p1[n + 1] = ’