1                 : /*
       2                 :  *  methods/iterate.c
       3                 :  *  
       4                 :  *  Calculate the sum of a given range of integer numbers.
       5                 :  *
       6                 :  *  This particular method of implementation works by way of brute force,
       7                 :  *  i.e. it iterates over the entire range while adding the numbers to finally
       8                 :  *  get the total sum. As a positive side effect, we're able to easily detect
       9                 :  *  overflows, i.e. situations in which the sum would exceed the capacity
      10                 :  *  of an integer variable.
      11                 :  *
      12                 :  */
      13                 : 
      14                 : #include <stdio.h>
      15                 : #include <stdlib.h>
      16                 : #include "iterate.h"
      17                 : 
      18                 : 
      19                 : int iterate_get_sum (int min, int max)
      20               3 : {
      21               3 :         int i, total;
      22                 : 
      23               3 :         total = 0;
      24                 : 
      25                 :         /* This is where we loop over each number in the range, including
      26                 :            both the minimum and the maximum number. */
      27                 : 
      28           67548 :         for (i = min; i <= max; i++)
      29                 :         {
      30                 :                 /* We can detect an overflow by checking whether the new
      31                 :                    sum would become negative. */
      32                 : 
      33           67546 :                 if (total + i < total)
      34                 :                 {
      35               1 :                         printf ("Error: sum too large!\n");
      36               1 :                         exit (1);
      37                 :                 }
      38                 : 
      39                 :                 /* Everything seems to fit into an int, so continue adding. */
      40                 : 
      41           67545 :                 total += i;
      42                 :         }
      43                 : 
      44               2 :         return total;
      45                 : }