牛客网[编程题] 页码统计（Java实现）

牛牛新买了一本算法书，算法书一共有n页，页码从1到n。牛牛于是想了一个算法题目：在这本算法书页码中0~9每个数字分别出现了多少次？ 

输入描述:

输入包括一个整数n(1 ≤ n ≤ 1,000,000,000)

输出描述:

输出包括一行10个整数，即0~9这些数字在页码中出现的次数，以空格分隔。行末无空格。

输入例子:

999

输出例子:

189 300 300 300 300 300 300 300 300 300

//参考自：牛客网用户：gs54package page.of.statistics;import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner sc = new Scanner(System.in);while (sc.hasNextInt()) {int n = sc.nextInt();int arr[] = new int[10];for (int i = 0; i < 10; i++) {arr[i] = 0;}count(n, arr);for (int i = 0; i < 9; i++) {System.out.print(arr[i] + " ");}System.out.print(arr[9]);}sc.close();}public static void count(int n, int arr[]) {for (int i = 1; n / i != 0; i *= 10) {//394 i=1时，before=39 after=0 current=4;// i=10 before=3 after=3,current=9;int before = n / (i * 10);int after = n % i;int current = (n / i) % 10;//统计当前循环0的个数if (current == 0) {arr[0] += (before - 1) * i + after + 1;} else {arr[0] += before * i;}//统计当前current循环1至9的个数for (int index = 1; index < 10; index++) {if (index < current) {arr[index] += (1 + before) * i;} else if (index == current) {arr[index] += before * i + after + 1;} else {arr[index] += before * i;}}}}}