Just PHP FUN 069.

just_php_fun_069.md

Just PHP FUN 069.

• https://www.codewars.com/kata/56bdd0aec5dc03d7780010a5 Basics 08: Find next higher number with same Bits (1's).

Started at 21:33 06.08.2020 Thursday Aug.
Finished at 22:46 06.08.2020 Thursday Aug. (1hr 13minutes)

nextHigher.php

<?php
# https://www.geeksforgeeks.org/next-higher-number-with-same-number-of-set-bits/
# https://www.codewars.com/kata/56bdd0aec5dc03d7780010a5 Basics 08: Find next higher number with same Bits (1's).
function nextHigher($x) {
 $next = 0; 
      
    if($x) 
    { 
      
        // right most set bit 
        $rightOne = $x & - $x; 
      
        // reset the pattern and set next higher  
        // bit left part of x will be here 
        $nextHigherOneBit = $x + $rightOne; 
      
        // nextHigherOneBit is now part [D] of  
        // the above explanation. 
      
        // isolate the pattern 
        $rightOnesPattern = $x ^ $nextHigherOneBit; 
      
        // right adjust pattern 
        $rightOnesPattern = intval(($rightOnesPattern) /  
                                            $rightOne); 
      
        // correction factor 
        $rightOnesPattern >>= 2; 
      
        // rightOnesPattern is now part [A]  
        // of the above explanation. 
      
        // integrate new pattern (Add [D] and [A]) 
        $next = $nextHigherOneBit | $rightOnesPattern; 
    } 
  
    return $next;
}

function nextHigher($n) {
  echo "$n \n";
  $n = decbin($n);
  echo "$n - input\n";
  for($i = strlen($n) - 1, $j = strlen($n) - 2; $j > 0; $i -=1, $j-=1)
    if('0' == $n[$j] && '1' == $n[$i]){
      $n[$j] = '1'; $n[$i] = '0';
      echo "$n - output \n";
      return bindec($n);
    }
  
   $ones = substr_count($n,'1'); $zeros = substr_count($n,'0');
  return bindec("1".str_repeat('0',$zeros+1).str_repeat('1',$ones-1));
}