HDU2451:Simple Addition Expression
The yacht is equipped with the most advanced navigation and driving system which can all be manipulated by a computer. When the captain notices that there is only gentle breeze and the sea waves are not high, he starts the autopilot. The yacht sails forward
smoothly, ploughs the waves. When it’s completely dark, the passengers start to feel a little funny for sudden forward rushes or sudden decelerations or slight swings. The captain immediately walks to the driving platform and switches the autopilot to human
manipulation. The yacht returns back to normal and the party restarts. Laughers come back, too.
The captain summons the engineer on board to do a thorough check of the navigation system. It turns out that only the computer is out of order, but the exact failure is still unclear. There is a computer scientist among the passengers who is also invited to
the cab to give a hand. He first inputs several groups of data to test the computer. When he inputs 1+2+3, the computer outputs 6, which is exactly right. But when he inputs 4+5+6, the computer outputs 5, which is wrong. Then he inputs 12+13+14, and gets 39,
another right answer, while he inputs 14+15+16, and gets 35, another wrong answer. After the test, the computer scientist says smilingly: “the failure is clear now. The computer's adder can not carry." After excluding the failure, the captain restarts the
autopilot and the yacht returns back to normal, sailing smoothly on the sea.
The captain and the engineer invite the computer scientist to sit down and have a talk. The computer scientist tells a story as following:
A former mathematician defined a kind of simple addition expression.
If there is an expression (i) + (i+1) + (i+2), i>=0, when carried out additive operations, no position has a carry, it is called simple addition expression.
For instance, when i equals 0, 0+1+2 is a simple addition expression, meanwhile when i equals 11, 11+12+13 is a simple addition expression, too. Because of that no position has a carry.
However, when i equals 3, 3+4+5 is not a simple addition expression, that is because 3+4+5 equals 12, there is a carried number from unit digit to tens digit. In the same way, when i equals 13, 13+14+15 is not a simple addition expression, either. However,
when i equals 112, 112+113+114 is a simple addition expression. Because 112+113+114 equals 339, there is no carry in the process of adding.
when the students have got the definition of simple addition expression, the mathematician puts forward a new question: for a positive integer n, how many simple addition expressions exist when i<n. In addition, i is the first number of a simple addition expression.
when the value of n is large enough, the problem needs to be solved by means of computer.
1
2
3
4
10
11
1
2
3
3
3
4
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
#define ll __int64
ll n; ll solve(ll n)
{
ll p,ans = 0,tem,mod = 1e9,t;
if(!n) return 0;
while(n)
{
p = n/mod;
if(p>=4)
{
t = 1;
while(n)
{
t*=4;
n/=10;
}
ans += t/4*3;
}
else
{
tem = n/10;
t = p;
if(!tem)
ans+=t;
else
{
while(tem)
{
t*=4;
tem/=10;
}
ans+=t/4*3;
}
}
n%=mod;
mod/=10;
}
return ans;
} int main()
{
while(~scanf("%I64d",&n))
printf("%I64d\n",solve(n)); return 0;
}
HDU2451:Simple Addition Expression的更多相关文章
- 组合数学第一发 hdu 2451 Simple Addition Expression
hdu 2451 Simple Addition Expression Problem Description A luxury yacht with 100 passengers on board ...
- HDU 2451 Simple Addition Expression(组合数学)
主题链接:http://acm.hdu.edu.cn/showproblem.php?pid=2451 Problem Description A luxury yacht with 100 pass ...
- 【计数】Simple Addition Expression
[来源] 2008年哈尔滨区域赛 [题目链接]: http://acm.hdu.edu.cn/showproblem.php?pid=2451 [参考博客]: HDU 2451 Simple Addi ...
- 【HDOJ】2451 Simple Addition Expression
递推,但是要注意细节.题目的意思,就是求s(x) = i+(i+1)+(i+2),i<n.该表达中计算过程中CA恒为0(包括中间值)的情况.根据所求可推得.1-10: 31-100: 3*41- ...
- HDU 2451 Simple Addition Expression
题目大意:有一个关于 简单加法表达式 的定义告诉你,就是 选一个数字i 如果 i+(i+1)+(i+2) 它的和,没有任何一位进位的话,那就是 一个i的简单加法表达式,求小于n的表达式数目. 题 ...
- hdu 2451 Simple Addition Expression(数位DP )成败在于细节
亚洲区域赛的题,简单的数位DP题,注重细节. 任何细节都有可能导致wa,所以没有绝对的水题. 把握好细节,此题便A. #include<stdio.h> __int64 getans(__ ...
- HDU 2451 Simple Addition Expression(找规律,考验智商)
题目 最近比赛的题目好多签到题都是找规律的考验智商的题目啊,,,我怎么越来越笨了,,,, 通过列举,可以发现规律: 从左往右按位扫这个数: 当数的长度大于1时: 当首位大于3时,答案就是4*4*4*… ...
- 10994 - Simple Addition(规律)
Problem E Simple Addition Input: Standard Input Output: Standard Output Let’s define a simple recurs ...
- uva 10994 - Simple Addition(规律)
题目链接:uva 10994 - Simple Addition 题目大意:给出l和r,求∑(l≤i≤r)F(i), F(i)函数题目中有. 解题思路:由两边向中间缩进,然后l和r之间的数可以按照1~ ...
随机推荐
- Android中目的地Intent的使用
一.什么是Intent? Intent的中文意思是目的.在Android中也是“目的”的意思.就是我们要去哪里,从这个activity要前往另一个Activity就需要用到Intent. 示例代码一: ...
- Effective C++ Item 33 避免遮掩继承过来的名称
本文为senlie原创,转载请保留此地址:http://blog.csdn.net/zhengsenlie ? 不懂 c++为什么derived classes 内的名称要遮掩 base classe ...
- HDU1028Ignatius and the Princess III母函数入门
这个题也能够用递归加记忆化搜索来A,只是因为这题比較简单,所以用来做母函数的入门题比較合适 以展开后的x4为例,其系数为4,即4拆分成1.2.3之和的拆分数为4: 即 :4=1+1+1+1=1+1+2 ...
- PHP 类属性 类静态变量的访问
php的类属性其实有两种,一种是类常量,一种是类静态变量.两种容易引起混淆. 如同静态类方法和类实例方法一样,静态类属性和实例属性不能重定义(同名),但静态属性可以和类常量同名. <?php c ...
- 【深入浅出jQuery】源码浅析--整体架构(转)
最近一直在研读 jQuery 源码,初看源码一头雾水毫无头绪,真正静下心来细看写的真是精妙,让你感叹代码之美. 其结构明晰,高内聚.低耦合,兼具优秀的性能与便利的扩展性,在浏览器的兼容性(功能缺陷.渐 ...
- android下获取无线wif信号、ssid、MAC等操作类
一个android下获取无线wif信号.ssid.MAC等操作的类. WifiAdmin.java package com.afu; import java.util.List; import and ...
- VMWare网络设置的3中方式(转)
一 VMware网络设置的三种方式 1 Host-only连接方式 让虚机具有与宿主机不同的各自独立IP地址,但与宿主机位于不同网段,同时为宿主主机新增一个IP地址,且保证该IP地址与各虚机IP地址 ...
- 联想A798T刷机包 基于百度云V6 集成RE3.1.7美化版 精简冗余文件
ROM介绍 1.apk进行odex合并及zipaliang优化-省电及降低内存暂用. 2.測试相机.通话.数据.wifi.蓝牙.等传感器均正常,. 3.提供时间居中防iphone状态栏补丁 4.增加I ...
- 认识Underscore
Underscore一个JavaScript实用库,提供了一整套函数式编程的实用功能,但是没有扩展任何JavaScript内置对象.它弥补了部分jQuery没有实现的功能,同时又是Backbone.j ...
- c#获取页面重定向url
/// <summary> /// 获取页面重定向url /// </summary> /// <param name="url"></p ...