今天晴天

上帝让我高考RP爆发是要我明白时间的性价比是个因变量;上帝没让我实现最初的梦想是为了告诫我性价比是有价的。

做最好的自变量吧

带着梦想一同呼吸，让梦不落！

Fighting

本地安装

我使用的是:

1. MediaWiki: 1.8.4
2. PHP: 5.2.5 (apache2handler)
3. MySQL: 5.0.45-community-nt
4. Extensions:

   * Extension functions:
         o wfSyntaxExtension

是在windows系统下安装，选择了wamp+mediaWiki组合，wamp安装很简单，wiki安装可以参见allwiki的教程（大家 google吧）。我是搭建在移动硬盘上的，所以每次换机器的时候就得注意了。首先要保证盘符一致，接着保证wamp所有服务开启；一般apache服务的80端口会被占用，在命令提示符下输入：netstat -ano 找到对应的pid 服务名，接着利用任务管理器停止该服务，再启动wampapache服务即可。

black	#000000		silver	#c0c0c0		maroon	#800000		red	#ff0000
navy	#000080		blue	#0000ff		purple	#800080		fuchsia	#ff00ff
green	#008000		lime	#00ff00		olive	#808000		Yellow	#ffff00
teal	#008080		aqua	#00ffff		gray	#808080		white	#ffffff

3

3 5 6 4 2 1 3 5 7 6 4 2 3 5 4

2 1 -2 -2 -1 2 2 2 -1 -2 -2 1 2 -1

4

4 6 7 5 3 2 4 6 8 9 7 5 3 1 2 4 6 8 7 5 3 4 6 5

2 1 -2 -2 -1 2 2 2 1 -2 -2 -2 -2 1 2 2 2 -1 -2 -2 1 2 -1

5

5 7 8 6 4 3 5 7 9 10 8 6 4 2 1 3 5 7 9 11 10 8 6 4 2 3 5 7 9 8 6 4 5 7 6

2 1 -2 -2 -1 2 2 2 1 -2 -2 -2 -2 -1 2 2 2 2 2 -1 -2 -2 -2 -2 1 2 2 2 -1 -2 -2 1 2 -1

6

6 8 9 7 5 4 6 8 10 11 9 7 5 3 2 4 6 8 10 12 13 11 9 7 5 3 1 2 4 6 8 10 12 11 9 7 5 3 4 6 8 10 9 7 5 6 8 7

2 1 -2 -2 -1 2 2 2 1 -2 -2 -2 -2 -1 2 2 2 2 2 1 -2 -2 -2 -2 -2 -2 1 2 2 2 2 2 -1 -2 -2 -2 -2 1 2 2 2 -1 -2 -2 1 2 -1

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    ifstream fin("shuttle.in");
    int m;
    fin >> m;
    int flag = -1;   
    int n = m+1;
    int t = 0;   
    int i,j;

    ofstream fout("shuttle.out");
    for ( i=1; i<=m; i++)
    {
        n += flag;
            (++t % 20 == 0 )? fout << n << endl : fout << n << ' ';
        flag *= -1;
        for ( int j=0; j<i ; j++)
        {
            n += flag*2;
            (++t % 20 == 0 )? fout << n << endl : fout << n << ' ';
        }
    }
    for ( i=m; i>1; i--)
    {
        flag *= -1;
        n += flag;
        (++t % 20 == 0 )? fout << n << endl : fout << n << ' ';
        for ( j=1; j<i; j++)
        {
            n += flag*2;
            (++t % 20 == 0 )? fout << n << endl : fout << n << ' ';
        }
    }
    fout << n-flag << endl;

    return 0;
}

Executing...

           Test 1: TEST OK [0 secs]
           Test 2: TEST OK [0.004 secs]
           Test 3: TEST OK [0.004 secs]
           Test 4: TEST OK [0 secs]
           Test 5: TEST OK [0.004 secs]
           Test 6: TEST OK [0 secs]
           Test 7: TEST OK [0 secs]
           Test 8: TEST OK [0.004 secs]
           Test 9: TEST OK [0 secs]
           Test 10: TEST OK [0.004 secs]
     
     All tests OK.

DFS


Executing...
      Test 1: TEST OK [0 secs]
      Test 2: TEST OK [0 secs]
      Test 3: TEST OK [0.004 secs]
      Test 4: TEST OK [0 secs]
      Test 5: TEST OK [0 secs]
      Test 6: TEST OK [0 secs]
      Test 7: TEST OK [0.004 secs]
      Test 8: TEST OK [0.004 secs]
      Test 9: TEST OK [0.004 secs]
      Test 10: TEST OK [0 secs]
      Test 11: TEST OK [0 secs]

All tests OK.

Executing...
      Test 1: TEST OK [0 secs]
      Test 2: TEST OK [0.04 secs]
      Test 3: TEST OK [0.06 secs]
      Test 4: TEST OK [0.04 secs]
      Test 5: TEST OK [0.08 secs]
      Test 6: TEST OK [0.028 secs]
      Test 7: TEST OK [0.028 secs]
      Test 8: TEST OK [0.4 secs]

All tests OK.

Analysis Rob Kolstad

This problem is only tricky for generating the proper gears to check ratios and coding so that it doesn't run too long. Tomek Czajka's program (below) does all these things well. Note how he generates the gear ratios in an order to reduce sorting time. His recursive gear generation is very elegant with very few extra steps.

Increasing speed with hashing

USA's Jacob Steinhardt writes:

Cowcycles can be solved much faster by hashing the gear ratios. If after the front gears are finished, the gear ratios for the front set have already been searched, we can stop. For example,

1 3 5 7

will give an equivalent variance to

2 6 10 14

or to

3 9 15 21

Thus we can eliminate a good portion of our search time.

&ME:
fEnd:=trunc(3*gearF[1]*r1/r2-fixed)+1;
rBeg:=trunc(gearF[f]*r2/(3*gearF[1])+fixed);