Connected Graph
| Time Limit: 1000MS | Memory Limit: 30000K | |
| Total Submissions: 3156 | Accepted: 1533 |
Description
An undirected graph is a set V of vertices and a set of E∈{V*V} edges.An undirected graph is connected if and only if for every pair (u,v) of vertices,u is reachable from v.
You are to write a program that tries to calculate the number of different connected undirected graph with n vertices.
For example,there are 4 different connected undirected graphs with 3 vertices.
You are to write a program that tries to calculate the number of different connected undirected graph with n vertices.
For example,there are 4 different connected undirected graphs with 3 vertices.
Input
The
input contains several test cases. Each test case contains an integer n,
denoting the number of vertices. You may assume that 1<=n<=50.
The last test case is followed by one zero.
Output
For each test case output the answer on a single line.
Sample Input
1 2 3 4 0
Sample Output
1 1 4 38
Source
————————————————我是华丽丽的分割线——————————————————
据说是男人八题中的第一道
难得我都快不会了...T_T
DP解决。