一本书的页码从自然数1 开始顺序编码直到自然数n。书的页码按照通常的习惯编排，每个页码都不含多余的前导数字0。例如，第6 页用数字6 表示，而不是06 或006 等。数字计数问题要求对给定书的总页码n，计算出书的全部页码中分别用到多少次数字0，1，2，…，9。-A book page from the start of the natural number sequence coding until the natural number n. The page number of the book in accordance with the usual custom layout, each page does not contain an extra leading digits 0. For example, on page 6, number 6 instead of 06 or 006. Digital counting requirements to the total number of pages of the book given n, the calculation of the full page of the book were used how many times the number 0, 1, 2, ..., 9.