JAVA:面试题：给定一个一亿长度的数组，数组元素中随机放了0~9，10个数字，要求你统计每个数出现的次数。

gistfile1.java

public class Test {
	public static void main(String[] args) {
		int[] a = new int[100000000];
		for (int i = 0; i < a.length; i++) {
			a[i] = (int) (Math.random() * 10);
		}
		int[] b = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
		long start = System.currentTimeMillis();
		for (int i = 0; i < a.length; i++) {
			b[a[i]] += 1;
		}
		long end = System.currentTimeMillis();
		System.out.println(end - start + " ms");
	}
}