Use PHP code to verify that a string of numbers is a method of connecting a digital string

This article mainly introduces the use of PHP to determine whether or not to multiply the number of strings of the example, the text through the example code introduced in very detailed, for everyone has a certain reference learning value, the need for friends below with a small series to learn.

Describe

With such a problem, given a number string A, you need to determine whether a is a hyphen number string, the definition of a hyphen string is that a number string can be split into several numbers, the following number (starting from the nth number) is the product of the preceding 2 digits.

Example

(1) ' 122 '---can be split into [1|2|2]

Result: 1x2=2 (tandem digit string)

(2) ' 1122242 '---can be split into [11|22|242]

Result: 11x22=242 (tandem digit string)

(3) ' 1224832256 '---can be split into [1|2|2|4|8| 32|256]

Result: 1x2=2,2x2=4,2x4=8,4x8=32,8x32=256 (tandem digit string)

(4) ' 234547898185239692 '---can be split into [23454|7898|185239692]

Result: 23454x7898=185239692 (tandem digit string)

(5) ' 113 ' can be disassembled [1|1|3]

Result: 1x1! = 3 (non-connected multiplication number string)

Code

/** * Determines if the string function * @param $strNum * @return bool **/function isexec ($strNum) {$str = (string) $strNum; for ($i = 0; $i &lt ; Strlen ($STR);  $i + +) {$k = 1;   for ($j = $i + 1; $j < strlen ($STR); $j + +) {$a _i = 0;   $b _i = $i + 1;   $p _i = $i + 1;   $m _i = $k + +;   $c _i = $b _i + $m _i;   $res = false;   $formula = [];    while (1) {$a = substr ($str, $a _i, $p _i);    $b = substr ($str, $b _i, $m _i);    $n = $a * $b;    $c = substr ($str, $c _i, strlen ($n)); Echo ' <br/> '. $a. '*' . $b. '=' . $n. ' and '. $c.    ' <br/> '; if ($c) {$formula [] = $a. '*' . $b. '=' .    $n;    if ($c = = = False | | $c = = = "") {break;     } if (Intval ($n) = = Intval ($c)) {$p _i = strlen ($b);     $m _i = strlen ($n);     $a _i = $b _i;     $b _i = $c _i;     $c _i = $b _i + $m _i;    $res = true;     } else {$res = false;    Break    }} if ($res = = = True) {Print_r ($formula);   return true; }//var_dump ($res).  ' <br/> '; }} return false;}

Perform

var_dump(isExec('1224832256'));

Running results array[   [0] = 1*2=2   [1] = 2*2=4   [2] = = 2*4=8   [3] = = 4*8=32   [4] = = 8*32=256] BOOL (TRUE)

var_dump(isExec('234547898185239692'));

Run result array[   [0] = 23454*7898=185239692]bool (True)

var_dump(isExec('1122242'));

Run result array[   [0] = 11*22=242]bool (True)

var_dump(isExec('11234'));

Run result bool (false)