路径规划 Adjacency matrix 传球问题

建模

问题是什么

知道了问题是什么答案就ok了

重复考虑与重复计算

程序可以重复考虑但往目标篮子中放入时，放不放把握好就ok了。

集合

交集

并集

路径规划

字符串处理

42423
42424
42432
42434
43123
43124
43132
43134
43142
43143
43212
43213
43214
43232
43234
43242
43243
43412
43413
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43423
43424
43432
43434
183well@well:/home/etc/project$ cat w.php
<?php
$wx = 0;
$pass = array(11,22,33,44,5,6,7,8,9,0);
for($w=11111;$w<44445;$w++){
    $w.='';
    if(substr($w,0,1)!=1 && substr($w,strlen($w)-1,1)!=1)
    {    $flag=0;
        foreach($pass as $val){
            $val .='';
            if(strpos($w,$val)!==false)$flag = 1;            
        }    
        if($flag == 0){echo $w,"
";$wx++;}            
    }
    $w += 1-1;
}
echo $wx;

die();

https://en.wikipedia.org/wiki/Adjacency_matrix

Undirected Graphs

The convention followed here (for undirected graphs) is that each edge adds 1 to the appropriate cell in the matrix, and each loop adds 2. This allows the degree of a vertex to be easily found by taking the sum of the values in either its respective row or column in the adjacency matrix.

Directed Graphs

In directed graphs, the in-degree of a vertex can be computed by summing the entries of the corresponding row, and the out-degree can be computed by summing the entries of the corresponding column.

传球问题的终极解法吴炜超
http://old.pep.com.cn/rjwk/gzsxsxkj/2011/sxkj4/sxkj4ts/201106/t20110623_1050797.htm