import java.util.*;public class Main { public static void main(String[] args) { // 构造从start到end的序列: final int start = 10; final int end = 20; List<Integer> list = new ArrayList<>(); for (int i = start; i <= end; i++) { list.add(i); } // 随机删除List中的一个元素: int removed = list.remove((int) (Math.random() * list.size())); int found = findMissingNumber(start, end, list); System.out.println(list.toString()); System.out.println("missing number: " + found); System.out.println(removed == found ? "测试成功" : "测试失败"); } static int findMissingNumber(int start, int end, List<Integer> list) { int i = 0; for (i = start; i <= end; i++) { if (i != list.get(i - start)) { break; } }return i; }}
Cecilia