编程介的小学生 2019-11-14 21:56 采纳率: 20.5%
浏览 137

Binary Stirling Numbers

Description

The Stirling number of the second kind S(n, m) stands for the number of ways to partition a set of n things into m nonempty subsets. For example, there are seven ways to split a four-element set into two parts:

{1, 2, 3} U {4}, {1, 2, 4} U {3}, {1, 3, 4} U {2}, {2, 3, 4} U {1}

{1, 2} U {3, 4}, {1, 3} U {2, 4}, {1, 4} U {2, 3}.

There is a recurrence which allows to compute S(n, m) for all m and n.

S(0, 0) = 1; S(n, 0) = 0 for n > 0; S(0, m) = 0 for m > 0;

S(n, m) = m S(n - 1, m) + S(n - 1, m - 1), for n, m > 0.

Your task is much "easier". Given integers n and m satisfying 1 <= m <= n, compute the parity of S(n, m), i.e. S(n, m) mod 2.

Example

S(4, 2) mod 2 = 1.

Task

Write a program which for each data set:
reads two positive integers n and m,
computes S(n, m) mod 2,
writes the result.
Input

The first line of the input contains exactly one positive integer d equal to the number of data sets, 1 <= d <= 200. The data sets follow.

Line i + 1 contains the i-th data set - exactly two integers ni and mi separated by a single space, 1 <= mi <= ni <= 10^9.
Output

The output should consist of exactly d lines, one line for each data set. Line i, 1 <= i <= d, should contain 0 or 1, the value of S(ni, mi) mod 2.
Sample Input

1
4 2
Sample Output

1

  • 写回答

0条回答 默认 最新

    报告相同问题?

    悬赏问题

    • ¥15 安卓adb backup备份应用数据失败
    • ¥15 eclipse运行项目时遇到的问题
    • ¥15 关于#c##的问题:最近需要用CAT工具Trados进行一些开发
    • ¥15 南大pa1 小游戏没有界面,并且报了如下错误,尝试过换显卡驱动,但是好像不行
    • ¥15 没有证书,nginx怎么反向代理到只能接受https的公网网站
    • ¥50 成都蓉城足球俱乐部小程序抢票
    • ¥15 yolov7训练自己的数据集
    • ¥15 esp8266与51单片机连接问题(标签-单片机|关键词-串口)(相关搜索:51单片机|单片机|测试代码)
    • ¥15 电力市场出清matlab yalmip kkt 双层优化问题
    • ¥30 ros小车路径规划实现不了,如何解决?(操作系统-ubuntu)