Advanced Search

Add 1 to a natural x.

/ Published in: C++
Save to your folder(s)
Code used to test the differences between "sum up a natural x 1", with or without recursion.

Expand | Embed | Plain Text

Copy this code and paste it in your HTML 
  1. /* 
  2.  * Add 1 to a natural x - Test with and without recursion.
  3.  * Author: Gil Mendes (gil0mendes)
  4.  *
  5.  * Created on 11 de Julho de 2012, 18:34
  6.  */
  7.  
  8. #include <cstdlib>
  9. #include <iostream>
  10.  
  11. #include <time.h>
  12.  
  13. using namespace std;
  14.  
  15. /**
  16.  * Add 1 to a natural x.
  17.  * 
  18.  * Function without recursion, very optimized.
  19.  * By Gil Mendes (gil0mendes)
  20.  * 
  21.  * @param int64_t number - Natural number (x)
  22.  * @return int64_t - Result
  23.  */
  24. int64_t add1ToX(register int64_t number) {
  25.     register int64_t total = 0;
  26.  
  27.     do {
  28.         total += number--;
  29.     } while (number != 0);
  30.  
  31.     return total;
  32. }
  33.  
  34. /**
  35.  * Add 1 to natural x (with recursion)
  36.  * 
  37.  * By Luciana Sondermann
  38.  * 
  39.  * @param int n - Natural number (x)
  40.  * @return int - Result
  41.  */
  42. int SomatRec(int n) {
  43.     int soma;
  44.     if (n == 1) {
  45.         soma = 1;
  46.     } else {
  47.         soma = n + SomatRec(n - 1);
  48.     }
  49.     return soma;
  50. }
  51.  
  52. void printResults(int64_t number, int64_t result, clock_t start, clock_t end) {
  53.     cout << "The sum of 1 to " << number << " is: " << result << endl;
  54.     cout << "Elapsed time (in microseconds): " << (end - start) << endl;
  55.  
  56.     return;
  57. }
  58.  
  59. /*
  60.  * Entry point of the program, tests the time between with and without recursion.
  61.  */
  62. int main(int argc, char** argv) {
  63.     int64_t number = 0, result = 0;
  64.     clock_t start, end;
  65.  
  66.     while (number <= 0) {
  67.         cout << "Enter a natural number: ";
  68.         cin >> number;
  69.     }
  70.  
  71.     cout << endl << "Without recursion" << endl;
  72.     start = clock();
  73.     result = add1ToX(number);
  74.     end = clock();
  75.     printResults(number, result, start, end);
  76.  
  77.     cout << endl << "With recursion" << endl;
  78.     start = clock();
  79.     result = SomatRec(number);
  80.     end = clock();
  81.     printResults(number, result, start, end);
  82.  
  83.     return 0;
  84. }

Report this snippet


Comments

RSS Icon Subscribe to comments

You need to login to post a comment.