title: Find Index Given Fibonacci Number Constant Time
signature: function find_index_given_fibonacci_number_constant_time(n)
test_code: 
  
  -- SOLUTION CODE
  -- ============================================
  PLACEHOLDER_CODE_BODY
  
  -- TESTING CODE 
  -- ============================================
  function isCorrect(actual, expected)
      if type(expected) ~= type(actual) then
          return false
      end
      
      if type(expected) == 'table' then
          for k,v_expected in pairs(expected) do
              
              if actual[k] == nil then
                  return false
              end
              local v_actual = actual[k]
              if not isCorrect(v_actual, v_expected) then
                  return false
              end
              actual[k]=nil
          end
      
          if next(actual) then 
              return false
          end
          return true
      else
          return actual == expected
      end
  end
  
  function validateSolution(actual, expected)
      return isCorrect(actual,expected)
  end
  
  function driver(n, expected)
      local exec_result;
      local status, error_msg = pcall(function () 
          exec_result=PLACEHOLDER_FN_NAME(n) 
      end)
      if status then
          if validateSolution(exec_result,expected) then
              return "PASSED"
          end
          return "FAILED"
      else
          return string.format("ERROR=%s",string.gsub(error_msg,".*:[%d]+: ",""))
      end
  end
      
  function main()
      result = driver(5, 5)
      print(string.format("TEST-0...%s",result))
  
      result = driver(19, 8)
      print(string.format("TEST-1...%s",result))
  
      result = driver(7, 6)
      print(string.format("TEST-2...%s",result))
  
      result = driver(94, 12)
      print(string.format("TEST-3...%s",result))
  
      result = driver(58, 11)
      print(string.format("TEST-4...%s",result))
  
      result = driver(65, 11)
      print(string.format("TEST-5...%s",result))
  
      result = driver(69, 11)
      print(string.format("TEST-6...%s",result))
  
      result = driver(96, 12)
      print(string.format("TEST-7...%s",result))
  
      result = driver(80, 11)
      print(string.format("TEST-8...%s",result))
  
      result = driver(14, 8)
      print(string.format("TEST-9...%s",result))
  
  end
  
  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;
  }