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  1. <?php
  2.     mb_internal_encoding('utf-8');
  3.  
  4.     function calculate($op, $numberText, $total) {
  5.         switch ($op) {
  6.                 case '':
  7.                     $total = floatval($numberText);
  8.                     break;
  9.                 case '+': 
  10.                     $total += floatval($numberText);
  11.                     break;
  12.                 case '-':
  13.                     $total -= floatval($numberText);
  14.                     break;
  15.                 case '*':
  16.                     $total *= floatval($numberText);
  17.                     break;
  18.                 case '/':
  19.                     $total /= floatval($numberText);
  20.                     break;
  21.         }
  22.         return $total;
  23.     }
  24.  
  25.     $operator = array('+', '-', '*', '=', '/');
  26.  
  27.     $input = '-2.43+3.62/2.1*9.02=';
  28.     $inputLength = mb_strlen($input);
  29.  
  30.     $numberText = '';
  31.     $result = 0;
  32.     $op = '';
  33.  
  34.     for ($i = 0; $i < $inputLength; $i++) {
  35.         $char = mb_substr($input, $i, 1);
  36.  
  37.         if (in_array($char, $operator)) {
  38.             if ($char == '=') {
  39.                 $result = calculate($op, $numberText, $result);
  40.             } else {
  41.                 $result = calculate($op, $numberText, $result);
  42.             }
  43.             echo "op = [$op], number = [$numberText], result = [$result], char = [$char]\n";
  44.             $numberText = '';
  45.             $op = $char;
  46.         } elseif (is_numeric($char) || $char == '.') {
  47.             $numberText .= $char;
  48.         } else {
  49.             echo "Непонятный символ. Работа программы прекращена\n";
  50.             exit();
  51.         }
  52.     }
  53.  
  54.     echo "{$input}{$result}";
Success #stdin #stdout 0.01s 52488KB
comments (?)
stdin 
Standard input is empty
stdout 
op = [], number = [], result = [0], char = [-]
op = [-], number = [2.43], result = [-2.43], char = [+]
op = [+], number = [3.62], result = [1.19], char = [/]
op = [/], number = [2.1], result = [0.56666666666667], char = [*]
op = [*], number = [9.02], result = [5.1113333333333], char = [=]
-2.43+3.62/2.1*9.02=5.1113333333333
https://ideone.com/gVfev9
language:
PHP (php 7.3.5)
created:
8 years ago
visibility:
secret

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