15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * methods/iterate.c 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Calculate the sum of a given range of integer numbers. 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This particular method of implementation works by way of brute force, 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * i.e. it iterates over the entire range while adding the numbers to finally 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * get the total sum. As a positive side effect, we're able to easily detect 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * overflows, i.e. situations in which the sum would exceed the capacity 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * of an integer variable. 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <stdio.h> 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <stdlib.h> 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "iterate.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)int iterate_get_sum (int min, int max) 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles){ 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int i, total; 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) total = 0; 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* This is where we loop over each number in the range, including 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) both the minimum and the maximum number. */ 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (i = min; i <= max; i++) 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* We can detect an overflow by checking whether the new 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) sum would become negative. */ 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (total + i < total) 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) printf ("Error: sum too large!\n"); 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) exit (1); 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* Everything seems to fit into an int, so continue adding. */ 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) total += i; 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return total; 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 46