third_party/lcov/example/methods/iterate.c

   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 {
  21         int i, total;
  22
  23         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         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                 if (total + i < total)
  34                 {
  35                         printf ("Error: sum too large!\n");
  36                         exit (1);
  37                 }
  38
  39                 /* Everything seems to fit into an int, so continue adding. */
  40
  41                 total += i;
  42         }
  43
  44         return total;
  45 }