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  1. <?php
  2.  
  3. function getLevel($base, $root = 3.0) {
  4.     $exact = pow($base, 1.0 / $root);
  5.     $ceil  = ceil($exact);
  6.     $floor = floor($exact);
  7.  
  8.     if (pow($exact, $root) == $base) { return $exact; }
  9.     if (pow($ceil,  $root) == $base) { return $ceil;  }
  10.     if (pow($floor, $root) == $base) { return $floor; }
  11.  
  12.     // No integer root
  13.     return FALSE;
  14. }
  15.  
  16. var_dump(getLevel(10648, 3)); // 22^3
  17. var_dump(getLevel(16807, 5)); //  7^5
  18.  
  19. var_dump(getLevel(1,  3)); // Should always return 1
  20. var_dump(getLevel(1, 99)); // Should always return 1
  21.  
  22. var_dump(getLevel(7)); // Has no integer 3rd root
  23.  
Success #stdin #stdout 0.01s 20568KB
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Standard input is empty
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float(22)
float(7)
float(1)
float(1)
bool(false)
https://ideone.com/VoABZx
language:
PHP (php 7.3.5)
created:
11 years ago
visibility:
public

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