In Ruby, when we create anobject, we want it to know how to perform certain actions- that is, we want it to have methods. In order for object to have methods, we can:
Second way is extremely easy and popular - it is so convinient, because once we define methods inside a class, we can create any number of instances of that class, and all of them will have these methods.
So classes define their instances' behavior - to certin point, at least, beecause we are always free to make any object unique, granting it with singleton methods.
As for modules, they are very much like classes- they define methods that objects will be using. Moreover, the Class class is a subclass of Module class , so all objects we work with are class object and module objects at the same time.What is the difference between classes and modules then? -A pretty significant one: modules cannot bring objects to life .That is , they cannot instantiate new oobjects. Only classes do so. In order for objects to know and have methods defined in any module, we have to mix that module into class. A lot of methods array objects have come from Enumerable module mixed-in Array class.
The idea of being able to mix modules in the class is great, because now we are not limited by classes' "single inheritance" rule, that allows any class to inherit behaviour of only one class. Having modules, we can bring many different behaviuors to our class, because we are free to mix any amount of modules into the class. So if we create instance of class Person, it will behave like all other persons do (for examle, it will have attributes like age, name, address, methods like #eat, #drink, #sleep, etc), but it can also behave like dancer if we mix in Dance module (with methods like #barre, #plie, #port_de_bras etc) , and like artist, social_drinker, and so on. If not for modules, we would have to define all the behaviours in the class, and then all objects of that class would have these behaviours. With modules, we get to mix-and-match , to get any combination of behaviours we like.
There are two ways to mix module into class - "include" and "prepend". The difference between them is how object searches and finds methods that come with included/prepended module. If you "include" module in the class, then method defined in that module searched for only if there is no method with same name defined in the class. If there is such method in the class definition, it gets executed, and method from the module package never gets executed. However, if we "prepend" module in the class,its methods will have first-class priority in method-lookup path, so they will always get executed.
While we mix modules into the classes, we can also define class inside module definition, like:
module Music
class Key
end
end
to create instance of class Key in this case, we need to use double-colon constant lookup:
a=Music::Key
This technique is used when we want to create class with similar name as another existent one.


Has the business, or anyone in the business, ever been penalised under the Estate Agents Act 1979?
This section is: Estate Agency Business
Examples of a penalty include:
- receiving a formal warning
- being banned from taking part in estate agency activities


Thanks to the following organizations who support the Hudson project with infrastructure and software
The Eclipse Foundation |
Hudson is a technology project at Eclipse and the Eclipse foundation kindly provides all of the infrastructure, support and administrative Framework to make a project such as Hudson successful. | |
Oracle |
Oracle provides the infrastructure used to support the Hudson-ci.org web site and the associated build farm used for Hudson Plugins and distribution bundles. Oracle also donates development and QA staff to the project. | |
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Atlassian provides free Open Source Project licenses to the Hudson project for Confluence wiki and JIRA Bug Tracking . | |
YourKit |
YourKit is kindly supporting Hudson open source projects with its full-featured Java Profiler. YourKit, LLC is the creator of innovative and intelligent tools for profiling Java and .NET applications. Take a look at YourKit's leading software products: YourKit Java Profiler and YourKit .NET Profiler. |


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Autonomous things is an emerging term for the technological developments that are expected to bring computers into the physical environment as autonomous entities without human direction, freely moving and interacting with humans and other objects. Self-navigating drones are the first AuT technology in (limited) deployment. It is expected that the first mass-deployment of AuT technologies will be the autonomous car, generally expected to be available around 2020. Other currently expected AuT technologies include home robotics (e.g., machines that provide care for the elderly, infirm or young), and military robots (air, land or sea autonomous machines with information-collection or target-attack capabilities).
Below is an infographic showing how autonomous cars could benefit society


Gully Boy producer Ritesh Sidhwani hopes to bring home an Oscars this year
by FilmfareGully Boy, directed by Zoya Akhtar and produced by Ritesh Sidhwani and Farhan Akhtar has been one of the finest films of the year. The much acclaimed film starring Alia Bhatt and Ranveer Singh is India's official entry in the International Feature Film category at the 92nd Academy Awards and the makers of films are leaving no stone unturned to ensure their film makes a mark at the Oscars this year.
Talking about his efforts, producer Ritesh Sidhwani said that his team is trying very hard to give Gully Boy all the necessary push. He told the media, “We are trying to bring the film to the forefront. We are doing everything within our power to make sure we leave no stone unturned in bringing the film there. The first shortlist will come out on 15th December, so we’re waiting for that."
Sharing this, Sidhwani further added, "After that 10 out of 93 films will advance (in the best international film category). So hopefully, we’ll make it to the shortlist then maybe we’ll get the award this time. Maybe, it’ll be the first time for India, so fingers crossed."


Jiajia’s Robot
问题描述 :
Jiajia wants to do some experiments on his two-eyed robot. Each eye of the robot shoots a very thin laser beam from it, which goes infinitely (i.e. a mathematical "ray"). Restricted by the internal structure, the two laser beams from the eyes must always form a right angle (i.e. two rays must be perpendicular to each other).
Fig. The collection of points from which the robot can localize itself.
The weird shape in the picture above is the collection of points from which the robot can localize itself. MA and MB are drawn as two line segments.
To help the robot localize itself, Jiajia placed two linear-shaped special materials called MA and MB. If one of the rays intersects with MA, while the other ray intersects with MB, the robot is able to gather enough spatial information for the localization.
The weird shape in the picture above is the collection of points from which the robot can localize itself. MA and MB are drawn as two line segments.
Though the task seems a little bit difficult, can you tell me the total area of these points?
输入:
There will be at most 50 test cases. Each case contains a single line of 8 positive integers x1, y1, x2, y2, x3, y3, x4, y4 not greater than 500, where (x1,y1) and (x2,y2) are two endpoints of MA, (x3,y3) and (x4,y4) are two endpoints of MB. Note that MA and MB can have at most one common point. Neither MA nor MB will be degenerated to a point. The last test case is followed by 8 zeros, which should not be processed.
输出:
There will be at most 50 test cases. Each case contains a single line of 8 positive integers x1, y1, x2, y2, x3, y3, x4, y4 not greater than 500, where (x1,y1) and (x2,y2) are two endpoints of MA, (x3,y3) and (x4,y4) are two endpoints of MB. Note that MA and MB can have at most one common point. Neither MA nor MB will be degenerated to a point. The last test case is followed by 8 zeros, which should not be processed.
样例输入:
264 280 147 360 162 335 320 334 203 165 288 227 149 295 153 344 0 0 0 0 0 0 0 0
样例输出:
Case 1: 26634.633 Case 2: 27436.383
#include <cstdio> #include <cstring> #include <cstdlib> #include <iostream> #include <algorithm> #include <cmath> #include <map> using namespace std; #define eps 1e-6 #define maxn 2010 #define pi acos(-1.0) #define ull unsigned long long inline double Sqr(double x){ return x*x; } struct Point { double x,y,r; Point(double _x,double _y, double _r):x(_x),y(_y),r(_r) {} Point() {} }; double dis( Point& p1, Point& p2 ) { double dx = p1.x - p2.x; double dy = p1.y - p2.y; return sqrt(dx*dx + dy*dy); } int n; Point tmp[maxn],p[maxn]; struct node { double k; int st; } ang[maxn]; inline int dblcmp( double x ) { if( fabs(x) < eps ) return 0; return x > 0 ? 1 : -1; } void get( Point c, double a, Point& p ) { p.x = c.x + c.r*cos(a); p.y = c.y + c.r*sin(a); } void adjust( double& x ) { while( dblcmp(x) < 0 ) x += 2*pi; while( dblcmp(x-2*pi) >= 0 ) x -= 2*pi; } bool inter_cir( Point& o1, Point& o2, double& p1, double& p2 ) { double d = dis(o1, o2); if( dblcmp(d-fabs(o1.r-o2.r)) <= 0 || dblcmp(d-o1.r-o2.r) >= 0 ) return 0; double cosa = (o1.r*o1.r + d*d - o2.r*o2.r) / (2*o1.r*d); double ang = acos(cosa); p1 = p2 = atan2( o2.y-o1.y, o2.x-o1.x ); p1 -= ang; adjust(p1); p2 += ang; adjust(p2); return 1; } int cmp( node a, node b ) { if( dblcmp(a.k - b.k) ) return a.k < b.k; return a.st > b.st; } double cross( Point& a, Point& b ) { return a.x*b.y - a.y*b.x; } double ans[20]; double solve() { int i, j, e, cnt, t; Point p1, p2; double pre, a, b; for( i = 0; i < n; ++i ) { t = 0; for( j = 0; j < n; ++j ) if( j != i ) { if( dblcmp(p[j].r - p[i].r - dis(p[i], p[j])) >= 0 ) t++; } e = 0; for( j = 0; j < n; ++j ) if( j != i ) { if( inter_cir(p[i], p[j], a, b) ) { ang[e].k = a; ang[e++].st = 1; ang[e].k = b; ang[e++].st = -1; if( dblcmp(a-b) > 0 ) { ang[e].k = 0; ang[e++].st = 1; ang[e].k = 2*pi; ang[e++].st = -1; } } } if( !e ) { ans[t] += pi*p[i].r*p[i].r; continue; } sort(ang, ang+e, cmp); cnt = 0; pre = ang[e-1].k - 2*pi; get(p[i], ang[e-1].k, p1); for( j = 0; j < e; ++j ) { ans[t+cnt] += 0.5*p[i].r*p[i].r*(ang[j].k-pre - sin(ang[j].k-pre)); get(p[i], ang[j].k, p2); ans[t+cnt] += cross(p1, p2)*0.5; p1 = p2; cnt += ang[j].st; pre = ang[j].k; } } return ans[0]-ans[n-1]; } Point get_cir(Point a,Point b) { Point t; t.x=(a.x+b.x)*0.5; t.y=(a.y+b.y)*0.5; t.r=dis(a,b)*0.5; return t; } int main() { Point a,b,c,d; int i,j,v,u,ok,k,tt=0; double x,y,dd; while(scanf("%lf %lf %lf %lf %lf %lf %lf %lf",&a.x,&a.y,&b.x,&b.y,&c.x,&c.y,&d.x,&d.y)!=EOF) { if(a.x==0&&a.y==0&&b.x==0&b.y==0&&c.x==0&&c.y==0&&d.x==0&&d.y==0) break; tmp[0]=get_cir(a,d); tmp[1]=get_cir(a,c); tmp[2]=get_cir(b,c); tmp[3]=get_cir(b,d); n=4;k=0; for( i = 0; i < n; ++i ) { ok = 1; if( !dblcmp(tmp[i].r) ) ok = 0; for( j = 0; ok && j < i; ++j ) { if( !dblcmp(tmp[j].x-tmp[i].x) && !dblcmp(tmp[j].y-tmp[i].y) && !dblcmp(tmp[j].r-tmp[i].r) ) ok = 0; } if( ok ) p[k++] = tmp[i]; } n = k; memset(ans,0,sizeof(ans)); printf("Case %d: %.3lf\n\n",++tt,solve()+eps); } return 0; }
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哦！你这么说就大亮了嘛！~~
不错的代码！
漏了一个"不"，已修正:)
#!/usr/bin/env python def cou(n): arr = [1]
对于第一题，我的直觉告诉我换不换都一样，求指教
等待后面的实现，多谢
懂了，谢谢啦
对，这里说的最长回文子序列，非子串
正解，已改正。应该都是protected
已修改。一些字符在编辑的时候转义了
这是研发的在线笔试题吗?发现很多C啊，阿里不是JAVA多么？
真心不错，力顶作者
分三种情况讨论。Not Possible就是impossible
这配图…..
这个问题别太纠结了，不同的编译器结果不一


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Dandeli is a town in the western Indian state of Karnataka that is located on the banks of River Kali
and
surrounded by mesmerizing green lush and dense woodland.
The place is encompassed with many popular places like-
Dandeli Wildlife Sanctuary is an abode to animals like monkeys, elephants including black panthers along with various bird species and also abundant plant diversities.
Kavala Caves is a notable temple of limestone caves that could offer you a lifetime remembering the adventurous experience as the temple is completely dark inside including snakes and bats.
Anshi National Park which got renamed as Kali Tiger Reserve is a complete package to withstand nature comprising deep valleys, flowing rivers with scenic mountains having a good balance of flora and fauna.
Water Rafting Destinations – Dandeli is one of the top white-water rafting destinations in India including activities like boating, kayaking, canoeing, water rafting or canoeing trips on the Kali River.
Apart from water activities, one can engage in other activities like cycling, mountain biking, nature walks, treks, angling trips, bird watching and crocodile spotting.
Come and be a part of this natural retreat and experience the wholesome fun while we offer you the best stays in order to ensure you take full pleasure in this recreation as per your budget and taste.
The place is encompassed with many popular places like-
Dandeli Wildlife Sanctuary is an abode to animals like monkeys, elephants including black panthers along with various bird species and also abundant plant diversities.
Kavala Caves is a notable temple of limestone caves that could offer you a lifetime remembering the adventurous experience as the temple is completely dark inside including snakes and bats.
Anshi National Park which got renamed as Kali Tiger Reserve is a complete package to withstand nature comprising deep valleys, flowing rivers with scenic mountains having a good balance of flora and fauna.
Water Rafting Destinations – Dandeli is one of the top white-water rafting destinations in India including activities like boating, kayaking, canoeing, water rafting or canoeing trips on the Kali River.
Apart from water activities, one can engage in other activities like cycling, mountain biking, nature walks, treks, angling trips, bird watching and crocodile spotting.
Come and be a part of this natural retreat and experience the wholesome fun while we offer you the best stays in order to ensure you take full pleasure in this recreation as per your budget and taste.
Homey Vibes, Dandeli Club Resorts
2 Days 1 Night
package starts from 1299/hd
package starts from 1299/hd
click to read more
2 Days 1 Night
Includes
- One Night Stay
- 3 Meals (Veg & Non-Veg Buffet)
- 10 Activities
3 Meals (Buffet Unlimited )
- 01 Dinner
- 01 Breakfast
- 01 Lunch
10 Activities
1)- Raft Boating
2)- Natural Jaccuzi Bath
3)- Jungle Trekking
4)- Rain Dance
5)- Night Campfire
6)- Zorbing
7)- Swimming Pool
8)- Cycling
9)- Archery
10)- Kayaking
Note:
-Transportation additional cost,
Cost may vary
around ₹300 - 500/Head
River Rafting Additional 500/-
per head 1km 40 Minute Ride
- Rafting availability is subject to water level
Resort No: 94823 61939
Washrooms will be common for camping Tents.
Breakfast :
+ Upma/Sheera
+ Idli Wada / Puri Bhaji
+ Bread Butter jam
+ Tea/Coffee
Lunch and Dinner:
+ Plain Rice
+ Jeera rice
+ Chapati
+ Chicken Curry
+ Curry +Pickle +Papad+Curd+Salad
+ Ice cream/Sweet
*Student group package 10% discount
*T&C
*Corporate package 10% discount
*T&C
Package of 2D 1N @ 799/per head.
Get closer to nature by making these beautiful and adventurous camping tents as you humble
abode in your trip & undergo a thrilling experience in your trip.
Package of 2D 1N @ 1299/per head.
Experience the feel of a tropical paradise nestled amidst woods for an ultimate laid back
luxury.
Jungle Safari Home Stay Resort is designed for nature lovers.
Package of 2D 1N @ 1299/per head.
Redefining the blend of elements that nature has in store for you, Dandeli Paradise offers
exclusive and affordable camping tents, deluxe cottage and rooms with a peaceful and unique
stay.
Package of 2D 1N @ 1299/per head.
Calming property surrounded by the flourishing green, to experience the refreshing air and
wind
from the tall trees and can encounter a lush recreation.
Package of 2D 1N @ 1799/per head.
River Resort will make you experience a cherishing memory for your lifetime as the resort is
the
perfect combination of luxury based accommodation along with encircling natural beauty.
Package of 2D 1N @ 2499/per head.
Star Resort, where leisure meets luxury.
The resort features beautiful, comfortable and sophisticated property along with an in-house
beautifully created garden and an outside mesmerizing view of Mother Nature.
THINGS TO DO IN DANDELI
Dandeli is not just a place of scenic beauty loaded with green lush and surrounded
everywhere
with Mother Nature the place is one of the top white-water rafting destinations in India and
comprises of many other activities mentioned like below.
 "
River Rafting
FIRE CAMPING
Nature walk
Farm visit
River Rafting
Jungle Safari
River Rafting
Bird Watching
Cycling
Boating