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  1. <?php
  2. error_reporting(-1);
  3. mb_internal_encoding('utf-8');
  4.  
  5. $input       = "2-2*2+5=";
  6. $inputLength = mb_strlen($input);
  7. $number      = 0;
  8. $result      = 0;
  9. $op          = '';
  10.  
  11. for ($i = 0; $i < $inputLength; $i++) {
  12.     $char = mb_substr($input, $i, 1);
  13.     if ($char == "*" || $char == "+" || $char == "-" || $char == "=") {
  14.         echo "op = [$op] result = [$result] number = [$number] char = [$char]\n";
  15.         if ($op == "+") {
  16.             $result += $number;
  17.         } elseif ($op == "-") {
  18.             $result -= $number;
  19.         } elseif ($op == "*") {
  20.             $result *= $number;
  21.         }
  22.         if ($char == "=") {
  23.         	if ($op == '') {$result = $number;}
  24.             echo $input . $result;
  25.         }
  26.  
  27.         if (($result == 0) & ($op == '')) {
  28.             $result = $number;
  29.         }
  30.         $op     = $char;
  31.         $number = 0;
  32.     } elseif (is_numeric($char)) {
  33.         $number = $number*10 + $char;
  34.     } else {
  35.         echo "Неверный символ: '$char'\n";
  36.     }
  37. }
  38.  
Success #stdin #stdout 0.01s 20520KB
comments (?)
stdin 
Standard input is empty
stdout 
op = [] result = [0] number = [2] char = [-]
op = [-] result = [2] number = [2] char = [*]
op = [*] result = [0] number = [2] char = [+]
op = [+] result = [0] number = [5] char = [=]
2-2*2+5=5
https://ideone.com/gbtlfj
language:
PHP (php 7.3.5)
created:
11 years ago
visibility:
public

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