归档:2012年5月月

JavaScript编程风格

杰拉斯 杰拉斯 | 时间:2012-05-05, Sat | 15,727 views
前端开发 

Douglas Crockford是Javascript权威,Json格式就是他的发明。

去年11月他有一个演讲(Youtube),谈到了好的Javascript编程风格是什么。
Douglas Crockford

我非常推荐这个演讲,它不仅有助于学习Javascript,而且能让你心情舒畅,因为Crockford讲得很幽默,时不时让听众会心一笑。

下面,我根据这个演讲和Crockford编写的代码规范,总结一下"Javascript编程风格"。

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[ACM_HDU_1052]Tian Ji -- The Horse Racing

杰拉斯 杰拉斯 | 时间:2012-05-03, Thu | 17,421 views
编程算法 

Tian Ji -- The Horse Racing

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 9786 Accepted Submission(s): 2718

Description

Here is a famous story in Chinese history.

"That was about 2300 years ago. General Tian Ji was a high official in the country Qi. He likes to play horse racing with the king and others."

"Both of Tian and the king have three horses in different classes, namely, regular, plus, and super. The rule is to have three rounds in a match; each of the horses must be used in one round. The winner of a single round takes two hundred silver dollars from the loser."

"Being the most powerful man in the country, the king has so nice horses that in each class his horse is better than Tian's. As a result, each time the king takes six hundred silver dollars from Tian."

"Tian Ji was not happy about that, until he met Sun Bin, one of the most famous generals in Chinese history. Using a little trick due to Sun, Tian Ji brought home two hundred silver dollars and such a grace in the next match."

"It was a rather simple trick. Using his regular class horse race against the super class from the king, they will certainly lose that round. But then his plus beat the king's regular, and his super beat the king's plus. What a simple trick. And how do you think of Tian Ji, the high ranked official in China?"

[ACM_HDU_1052]Tian Ji -- The Horse Racing

Were Tian Ji lives in nowadays, he will certainly laugh at himself. Even more, were he sitting in the ACM contest right now, he may discover that the horse racing problem can be simply viewed as finding the maximum matching in a bipartite graph. Draw Tian's horses on one side, and the king's horses on the other. Whenever one of Tian's horses can beat one from the king, we draw an edge between them, meaning we wish to establish this pair. Then, the problem of winning as many rounds as possible is just to find the maximum matching in this graph. If there are ties, the problem becomes more complicated, he needs to assign weights 0, 1, or -1 to all the possible edges, and find a maximum weighted perfect matching...

However, the horse racing problem is a very special case of bipartite matching. The graph is decided by the speed of the horses --- a vertex of higher speed always beat a vertex of lower speed. In this case, the weighted bipartite matching algorithm is a too advanced tool to deal with the problem.

In this problem, you are asked to write a program to solve this special case of matching problem.

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[ACM_ZJUT_1048]注释

杰拉斯 杰拉斯 | 时间:2012-05-02, Wed | 14,837 views
编程算法 

注释

Time Limit:1000MS Memory Limit:32768K

Description

给出一个C++源程序代码。请将其中的注释去掉。

Sample Input


//======================

// simplest program

//======================
#include<iostream>
using namespace std;
//----------------------
int main(){
cout<<”hello world!\n”;
}//---------------------

Sample Output

#include<iostream>
using namespace std;
int main(){
cout<<”hello world!\n”;
}

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