有26个字母{a-Z}和10个数字{0-9}
如果要生成8位字符的，区分大小写，
这样的排列是（26+26+10）8次方＝218340105584896个，这218万亿
但相邻不能有两个或以上相同的如{a1b2cc90，这个字符出现了两次cc}
这样的数据可以用PHP来产生吗？
如果生成单个文本数据应该不太可能，得切割成好多份……
这个意思？
$d = str_split('abcd');print_r(array_map('join', f(4, $d)));function f($n, $d) { $t = array_chunk($d, 1); if($n > 2) $t = f($n-1, $d); foreach($t as $x) foreach(array_chunk($d, 1) as $y) { if(end($x) != end($y)) $r[] = array_merge($x, $y); } return $r;}Array( [0] => abab [1] => abac [2] => abad [3] => abca [4] => abcb [5] => abcd [6] => abda [7] => abdb [8] => abdc [9] => acab [10] => acac [11] => acad [12] => acba [13] => acbc [14] => acbd [15] => acda [16] => acdb [17] => acdc [18] => adab [19] => adac [20] => adad [21] => adba [22] => adbc [23] => adbd [24] => adca [25] => adcb [26] => adcd [27] => baba [28] => babc [29] => babd [30] => baca [31] => bacb [32] => bacd [33] => bada [34] => badb [35] => badc [36] => bcab [37] => bcac [38] => bcad [39] => bcba [40] => bcbc [41] => bcbd [42] => bcda [43] => bcdb [44] => bcdc [45] => bdab [46] => bdac [47] => bdad [48] => bdba [49] => bdbc [50] => bdbd [51] => bdca [52] => bdcb [53] => bdcd [54] => caba [55] => cabc [56] => cabd [57] => caca [58] => cacb [59] => cacd [60] => cada [61] => cadb [62] => cadc [63] => cbab [64] => cbac [65] => cbad [66] => cbca [67] => cbcb [68] => cbcd [69] => cbda [70] => cbdb [71] => cbdc [72] => cdab [73] => cdac [74] => cdad [75] => cdba [76] => cdbc [77] => cdbd [78] => cdca [79] => cdcb [80] => cdcd [81] => daba [82] => dabc [83] => dabd [84] => daca [85] => dacb [86] => dacd [87] => dada [88] => dadb [89] => dadc [90] => dbab [91] => dbac [92] => dbad [93] => dbca [94] => dbcb [95] => dbcd [96] => dbda [97] => dbdb [98] => dbdc [99] => dcab [100] => dcac [101] => dcad [102] => dcba [103] => dcbc [104] => dcbd [105] => dcda [106] => dcdb [107] => dcdc)
