title: How To Turn Off A Particular Bit In A Number
signature: function howToTurnOffAParticularBitInANumber($n, $k) {
test_code: <?php
  
  
  // SOLUTION CODE 
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function validateSolution($actual, $expected){
      return serialize($actual) == serialize($expected);
  }
  
  function driver($n, $k, $expected){
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME($n, $k), $expected)){
          return "PASSED";
        }
        return "FAILED";
      }
      catch (Exception $exception_obj) {
        return get_class($exception_obj);
      }
  }
  
  function main(){
      printf("TEST-0...%s\n",driver(
        49, 15, 
        49));
      
      printf("TEST-1...%s\n",driver(
        59, 69, 
        59));
      
      printf("TEST-2...%s\n",driver(
        76, 20, 
        76));
      
      printf("TEST-3...%s\n",driver(
        27, 76, 
        27));
      
      printf("TEST-4...%s\n",driver(
        61, 60, 
        61));
      
      printf("TEST-5...%s\n",driver(
        67, 27, 
        67));
      
      printf("TEST-6...%s\n",driver(
        63, 71, 
        63));
      
      printf("TEST-7...%s\n",driver(
        85, 25, 
        85));
      
      printf("TEST-8...%s\n",driver(
        90, 64, 
        90));
      
      printf("TEST-9...%s\n",driver(
        24, 55, 
        24));
      
  }
  
  main();
  ?>
source_py: def how_to_turn_off_a_particular_bit_in_a_number(n, k):
      if (k <= 0):
          return n
      return (n & (~ (1 << (k - 1))))
source_cpp: int how_to_turn_off_a_particular_bit_in_a_number(int n, int k) {
    if ( k <= 0 ) return n;
    return ( n & ~ ( 1 << ( k - 1 ) ) );
  }