题目：输入一个正数s，打印出所有和为s 的连续正数序列（至少两个数）。

代码如下：

package demo;

import java.util.ArrayList;
import java.util.List;

/**
 * 和为s的连续正数序列
 * 
 * @author xiangdonglee
 *
 */
public class Test41_2 {
    public static List<List<Integer>> findContinuousSequence(int sum) {
        List<List<Integer>> result = new ArrayList<>();
        if (sum < 3) {
            return result;
        }
        int small = 1;
        int big = 2;
        int middle = (1 + sum) / 2;
        int curSum = small + big;
        while (small < middle) {
            if (curSum == sum) {
                List<Integer> list = new ArrayList<>(2);
                for (int i = small; i <= big; i++) {
                    list.add(i);
                }
                result.add(list);
            }
            while (curSum > sum && small < middle) {
                curSum -= small;
                small++;
                if (curSum == sum) {
                    List<Integer> list = new ArrayList<>(2);
                    for (int i = small; i <= big; i++) {
                        list.add(i);
                    }
                    result.add(list);
                }
            }
            big++;
            curSum += big;
        }
        return result;
    }

    public static void main(String[] args) {
        test2();
    }

    private static void test2() {
        System.out.println("和为1的连续正数序列：" + findContinuousSequence(1));
        System.out.println("和为3的连续正数序列：" + findContinuousSequence(3));
        System.out.println("和为4的连续正数序列：" + findContinuousSequence(4));
        System.out.println("和为9的连续正数序列：" + findContinuousSequence(9));
        System.out.println("和为15的连续正数序列：" + findContinuousSequence(15));
        System.out.println("和为100的连续正数序列：" + findContinuousSequence(100));
    }
}

来源：http://blog.csdn.net/derrantcm/article/details/46784423