title: Find Index Given Fibonacci Number Constant Time
signature: function findIndexGivenFibonacciNumberConstantTime($n) {
test_code: <?php
  
  
  // SOLUTION CODE 
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function validateSolution($actual, $expected){
      return serialize($actual) == serialize($expected);
  }
  
  function driver($n, $expected){
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME($n), $expected)){
          return "PASSED";
        }
        return "FAILED";
      }
      catch (Exception $exception_obj) {
        return get_class($exception_obj);
      }
  }
  
  function main(){
      printf("TEST-0...%s\n",driver(
        5, 
        5));
      
      printf("TEST-1...%s\n",driver(
        19, 
        8));
      
      printf("TEST-2...%s\n",driver(
        7, 
        6));
      
      printf("TEST-3...%s\n",driver(
        94, 
        12));
      
      printf("TEST-4...%s\n",driver(
        58, 
        11));
      
      printf("TEST-5...%s\n",driver(
        65, 
        11));
      
      printf("TEST-6...%s\n",driver(
        69, 
        11));
      
      printf("TEST-7...%s\n",driver(
        96, 
        12));
      
      printf("TEST-8...%s\n",driver(
        80, 
        11));
      
      printf("TEST-9...%s\n",driver(
        14, 
        8));
      
  }
  
  main();
  ?>
source_py: def find_index_given_fibonacci_number_constant_time(n):
      if (n <= 1):
          return n
      a = 0
      b = 1
      c = 1
      res = 1
      while (c < n):
          c = (a + b)
          res = (res + 1)
          a = b
          b = c
      return res
source_cpp: int find_index_given_fibonacci_number_constant_time(int n) {
    if ( n <= 1 ) return n;
    int a = 0, b = 1, c = 1;
    int res = 1;
    while ( c < n ) {
      c = a + b;
      res ++;
      a = b;
      b = c;
    }
    return res;
  }