112 lines
1.9 KiB
C
112 lines
1.9 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <string.h>
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/** Our old friend die from ex17. */
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void die(const char *message)
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{
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if(errno) {
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perror(message);
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} else {
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printf("ERROR: %s\n", message);
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}
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exit(1);
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}
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// a typedef creates a fake type, in this
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// case for a function pointer
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typedef int (*compare_cb)(int a, int b);
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/**
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* A classic bubble sort function that uses the
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* compare_cb to do the sorting.
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*/
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int *bubble_sort(int *numbers, int count, compare_cb cmp)
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{
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int temp = 0;
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int i = 0;
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int j = 0;
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int *target = malloc(count * sizeof(int));
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if(!target) die("Memory error.");
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memcpy(target, numbers, count * sizeof(int));
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for(i = 0; i < count; i++) {
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for(j = 0; j < count - 1; j++) {
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if(cmp(target[j], target[j+1]) > 0) {
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temp = target[j+1];
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target[j+1] = target[j];
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target[j] = temp;
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}
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}
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}
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return target;
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}
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int sorted_order(int a, int b)
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{
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return a - b;
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}
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int reverse_order(int a, int b)
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{
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return b - a;
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}
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int strange_order(int a, int b)
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{
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if(a == 0 || b == 0) {
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return 0;
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} else {
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return a % b;
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}
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}
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/**
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* Used to test that we are sorting things correctly
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* by doing the sort and printing it out.
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*/
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void test_sorting(int *numbers, int count, compare_cb cmp)
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{
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int i = 0;
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int *sorted = bubble_sort(numbers, count, cmp);
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if(!sorted) die("Failed to sort as requested.");
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for(i = 0; i < count; i++) {
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printf("%d ", sorted[i]);
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}
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printf("\n");
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free(sorted);
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}
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int main(int argc, char *argv[])
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{
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if(argc < 2) die("USAGE: ex18 4 3 1 5 6");
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int count = argc - 1;
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int i = 0;
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char **inputs = argv + 1;
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int *numbers = malloc(count * sizeof(int));
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if(!numbers) die("Memory error.");
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for(i = 0; i < count; i++) {
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numbers[i] = atoi(inputs[i]);
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}
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test_sorting(numbers, count, sorted_order);
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test_sorting(numbers, count, reverse_order);
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test_sorting(numbers, count, strange_order);
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free(numbers);
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return 0;
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}
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