2015 HIAST Collegiate Programming Contest H
A sequence of positive and non-zero integers called palindromic if it can be read the same forward and backward, for example:
15 2 6 4 6 2 15
20 3 1 1 3 20
We have a special kind of palindromic sequences, let's call it a special palindrome.
A palindromic sequence is a special palindrome if its values don't decrease up to the middle value, and of course they don't increase from the middle to the end.
The sequences above is NOT special, while the following sequences are:
1 2 3 3 7 8 7 3 3 2 1
2 10 2
1 4 13 13 4 1
Let's define the function F(N), which represents the number of special sequences that the sum of their values is N.
For example F(7) = 5 which are : (7), (1 5 1), (2 3 2), (1 1 3 1 1), (1 1 1 1 1 1 1)
Your job is to write a program that compute the Value F(N) for given N's.
Input
The Input consists of a sequence of lines, each line contains a positive none zero integer N less than or equal to 250. The last line contains 0 which indicates the end of the input.
Output
Print one line for each given number N, which it the value F(N).
Example
1
3
7
10
0
2
5
17
解题思路:
要求一个数能分解成的回文串的数量,首先他要想成为回文串,左右两边必须相等,奇偶性讨论:
1.当n为奇数时,有中间数字,且必为奇数,因为两边相等加起来必为偶数,那么中间的数字必为小于等于n的奇数,遍历中间数,对其中一边进行整数划分
2.当n为偶数是,有两种情况:
(1).n所化成的回文串长度为奇数,那么中间数必为偶数,直接按上面遍历划分就行,
(2).回文串长度为偶数时,直接对n/2进行整数划分。两种情况的值加起来就是n为偶数是能分解成的回文串数量
注意:整数划分最好不要用递归法,效率太低了,很容易超时。用dp打表还是比较稳的。而且数值比较大最好用long long。
实现代码:
#include<bits/stdc++.h>
using namespace std;
#define Max 255
#define ll long long
ll f[Max][Max];
void fun(){
for(int i=;i<;i++){
for(int j=;j<;j++){
if(i==||j==) f[i][j] = ;
else if(i==||j==) f[i][j] = ;
else if(i<j) f[i][j] = f[i][i];
else if(i==j) f[i][j] = f[i][j-] + ;
else f[i][j] = f[i-j][j] + f[i][j-];
}
}
}
int main()
{
ll ans,n,i;
fun();
//cout<<f[250][250]<<endl;
while(cin>>n&&n){
ans = ;
if(n%==){
for(i=;i<=n;i+=){
ans+=f[(n-i)/][i];
}
}
else{
for(i=;i<=n;i+=){
ans+=f[(n-i)/][i];
}
ans+=f[n/][n/];
}
cout<<ans<<endl;
}
return ;
}
2015 HIAST Collegiate Programming Contest H的更多相关文章
- Gym 100952H&&2015 HIAST Collegiate Programming Contest H. Special Palindrome【dp预处理+矩阵快速幂/打表解法】
H. Special Palindrome time limit per test:1 second memory limit per test:64 megabytes input:standard ...
- Gym 100952E&&2015 HIAST Collegiate Programming Contest E. Arrange Teams【DFS+剪枝】
E. Arrange Teams time limit per test:2 seconds memory limit per test:64 megabytes input:standard inp ...
- Gym 100952F&&2015 HIAST Collegiate Programming Contest F. Contestants Ranking【BFS+STL乱搞(map+vector)+优先队列】
F. Contestants Ranking time limit per test:1 second memory limit per test:24 megabytes input:standar ...
- The 2015 China Collegiate Programming Contest H. Sudoku hdu 5547
Sudoku Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 65535/65535 K (Java/Others)Total Subm ...
- Gym 100952J&&2015 HIAST Collegiate Programming Contest J. Polygons Intersection【计算几何求解两个凸多边形的相交面积板子题】
J. Polygons Intersection time limit per test:2 seconds memory limit per test:64 megabytes input:stan ...
- Gym 100952I&&2015 HIAST Collegiate Programming Contest I. Mancala【模拟】
I. Mancala time limit per test:3 seconds memory limit per test:256 megabytes input:standard input ou ...
- Gym 100952G&&2015 HIAST Collegiate Programming Contest G. The jar of divisors【简单博弈】
G. The jar of divisors time limit per test:2 seconds memory limit per test:64 megabytes input:standa ...
- Gym 100952D&&2015 HIAST Collegiate Programming Contest D. Time to go back【杨辉三角预处理,组合数,dp】
D. Time to go back time limit per test:1 second memory limit per test:256 megabytes input:standard i ...
- Gym 100952C&&2015 HIAST Collegiate Programming Contest C. Palindrome Again !!【字符串,模拟】
C. Palindrome Again !! time limit per test:1 second memory limit per test:64 megabytes input:standar ...
随机推荐
- NDK toolchain对应ABI
有些时候,解决一些问题,我们需要多一些耐心. 从今天起,正式开始SkylineGlobe移动端Android版本的二次开发. Application.mk修改为NDK_TOOLCHAIN := arm ...
- 4《想成为黑客,不知道这些命令行可不行》(Learn Enough Command Line to Be Dangerous)—目录
我们已经学习过许多处理文件的Unix工具,现在是时候来学习目录了,也就是文件夹(图20).正如我们所见,许多在文件中的开发思想也适用于目录,但同样也有许多区别.
- CF633H Fibonacci-ish II 莫队、线段树、矩阵乘法
传送门 这题除了暴力踩标程和正解卡常数以外是道很好的题目 首先看到我们要求的东西与\(Fibonacci\)有关,考虑矩阵乘法进行维护.又看到\(n \leq 30000\),这告诉我们正解算法其实比 ...
- docker部署rabbitMQ
获取rabbit镜像: docker pull rabbitmq:management 创建并运行容器: docker run -d --hostname my-rabbit --name rabbi ...
- 【亲测有效】Centos安装完成docker后启动docker报错docker: unrecognized service的两种解决方案
今天在学习Docker的时候 使用yum install docker安装完后启动不了,报错如下: [root@Sakura ~]# service docker start docker: unre ...
- [原]Veracrypt使用Yubikey作为安全令牌
今天刚刚到货Yubikey 5 美亚 直邮 ,易客满国际,国内居然是顺丰配送,点个赞. 必备的控件 https://developers.yubico.com/yubikey-manager-qt/R ...
- 个人阅读作业2—《No Silver Bullet: Essence and Accidents of Software Engineering》读后感
在进行了一次结对编程.一次团队编程和一次个人编程项目后,读了<No Silver Bullet: Essence and Accidents of Software Engineering> ...
- 软工个人作业-博客作业-WEEK2
1.是否需要代码规范: (1)这些规范都是官僚制度下产生的浪费大家的编程时间.影响人们开发效率, 浪费时间的东西. 首先来说,从短期上和个体上来看,一个团队的代码风格必然会在一定程 ...
- Week2 代码复查
代码复查 http://blog.fogcreek.com/increase-defect-detection-with-our-code-review-checklist-example/ 这篇博客 ...
- 团队项目第二周spec设计
本系统针对局域网进行联机聊天.聊天室分为服务器端和和客户端俩部分,服务器端程序主要 负责侦听客户端发来的信息,客户端需要登录到服务器端才可以实现正常的聊天功能. 1.本软件是一款局域网聊天软件,不能进 ...