编程珠玑(1)
开始看了下编程珠玑，书的开篇就是一个排序的问题，今天就来实践一下，稍作修改，如题目大意：生成1千万个1亿以内的不重复的数据集合.
public final static int count = 100000000;private static boolean[] collect = new boolean[count];private static int[] source = new int[count/10];public void createDate() {int temp = 0;for(int i = 0; i < count/10;) { temp = new Random().nextInt(count);if(!collect[temp]) {source[i] = temp;collect[temp] = true;System.out.println(i + " = " + source[i] );i++;}}}?这通过boolean来标识的话，速度确实加快了不少，直接变为了近O(n)了，不知道还能不能进行改进~~~
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public final static int count = 10000000;private static boolean[] collect = new boolean[count];private int[] source = new int[count/10];// 采用Floyd算法生成10000000个0~100000000之间的无重复随机整数，并对其进行排序public void sort() {int n = count;int m = count / 10;int temp = 0;for (int i = n-m; i < n; i ++) {temp = new Random().nextInt(n);if (!collect[temp]) {source[i-n+m] = temp;collect[temp] = true;} else {source[i-n+m] = i;collect[i] = true;}}}