title: Find Index Given Fibonacci Number Constant Time
signature: int findIndexGivenFibonacciNumberConstantTime(int n) {
test_code: #include <algorithm>
  #include <assert.h>
  #include <cstdlib>
  #include <iostream>
  #include <map>
  #include <set>
  #include <string>
  #include <tuple> 
  #include <unordered_map>
  #include <vector>
  #include <math.h>
  #include <cmath>
  #include <bits/stdc++.h>
  #include <numeric>
  #include <functional>
  
  using namespace std;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  bool validateSolution(int actual, int expected){
      return actual == expected;
  }
  
  string driver(int n, int expected){
      try
      {
          if (validateSolution(PLACEHOLDER_FN_NAME(n), expected)){
              return "PASSED";
          }
          return "FAILED";
      }
      catch (const std::overflow_error& exception_obj)
      {
          return typeid(exception_obj).name();
      }
      catch (const std::runtime_error& exception_obj)
      {
          return typeid(exception_obj).name();
      }
      catch (const std::exception& exception_obj)
      {
          return typeid(exception_obj).name();
      }
      catch (...)
      {
          return "UNK_ERROR";
      }
  }
  
  int main() {
      string result = "";
  
      result = driver(5, 5); 
      cout << "TEST-" << 0 << "..."
           <<  result
           << "\n";
  
      result = driver(19, 8); 
      cout << "TEST-" << 1 << "..."
           <<  result
           << "\n";
  
      result = driver(7, 6); 
      cout << "TEST-" << 2 << "..."
           <<  result
           << "\n";
  
      result = driver(94, 12); 
      cout << "TEST-" << 3 << "..."
           <<  result
           << "\n";
  
      result = driver(58, 11); 
      cout << "TEST-" << 4 << "..."
           <<  result
           << "\n";
  
      result = driver(65, 11); 
      cout << "TEST-" << 5 << "..."
           <<  result
           << "\n";
  
      result = driver(69, 11); 
      cout << "TEST-" << 6 << "..."
           <<  result
           << "\n";
  
      result = driver(96, 12); 
      cout << "TEST-" << 7 << "..."
           <<  result
           << "\n";
  
      result = driver(80, 11); 
      cout << "TEST-" << 8 << "..."
           <<  result
           << "\n";
  
      result = driver(14, 8); 
      cout << "TEST-" << 9 << "..."
           <<  result
           << "\n";
  
      return 0;
  }
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;
  }