mirror of
https://github.com/mfocko/blog.git
synced 2024-11-22 21:13:47 +01:00
141 lines
3.2 KiB
C
141 lines
3.2 KiB
C
#include <assert.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
/* If you want to see arrays before and after sorting, uncomment next line */
|
|
// #define DEBUG_OUTPUT
|
|
|
|
/**
|
|
* @brief Swaps two elements at given addresses.
|
|
* @param left Pointer to the first element.
|
|
* @param right Pointer to the second element.
|
|
*/
|
|
void swap(int *left, int *right)
|
|
{
|
|
/* TODO */
|
|
}
|
|
|
|
/**
|
|
* @brief Get index of biggest element in the array.
|
|
* @param ptr Pointer to the first element of the array.
|
|
* @param count Count of the elements in the array.
|
|
* @returns Index of the biggest element given the ordering.
|
|
*/
|
|
size_t maximum(int *ptr, size_t count)
|
|
{
|
|
/* Pseudocode:
|
|
* ===========
|
|
* max_index <- 0
|
|
* FOR i <- 1 TO n - 1 DO
|
|
* IF A[i] > A[max_index] THEN
|
|
* max_index <- i
|
|
* FI
|
|
* OD
|
|
* RETURN max_index
|
|
*/
|
|
/* TODO */
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* @brief Sort array in-situ using select-sort.
|
|
* @param ptr Pointer to the first element of the array.
|
|
* @param count Count of the elements in the array.
|
|
*/
|
|
void select_sort(int *ptr, size_t count)
|
|
{
|
|
/* Pseudocode:
|
|
* ===========
|
|
* FOR i <- n - 1 DOWNTO 1 DO
|
|
* j <- MAXIMUM(A, i + 1)
|
|
* SWAP(A, i, j)
|
|
* OD
|
|
*/
|
|
/* TODO */
|
|
}
|
|
|
|
// #pragma region TESTS
|
|
/**
|
|
* @brief Check if array is sorted.
|
|
* @param ptr Pointer to the first element of the array.
|
|
* @param count Count of the elements in the array.
|
|
*/
|
|
static void check_if_sorted(int *ptr, size_t count)
|
|
{
|
|
int *left = ptr;
|
|
int *right = ptr + 1;
|
|
|
|
for (size_t i = 0; i < count - 1; i++) {
|
|
assert(*left <= *right);
|
|
|
|
left++;
|
|
right++;
|
|
}
|
|
}
|
|
|
|
#ifdef DEBUG_OUTPUT
|
|
/**
|
|
* @brief Print numbers from an array.
|
|
* @param array Pointer to the first element of the array.
|
|
* @param count Count of the elements in the array.
|
|
*/
|
|
static void print_numbers(int *array, size_t count)
|
|
{
|
|
for (size_t i = 0; i < count; i++) {
|
|
printf(" %d", array[i]);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* @brief Run some basic tests on integer arrays.
|
|
*/
|
|
static void check_int_arrays()
|
|
{
|
|
/* You are free to add any other examples you like, in case you want to add
|
|
* array with more than 10 elements, please adjust the size.
|
|
*/
|
|
|
|
size_t examples_count = 5;
|
|
int examples[][10] = {
|
|
{ -1, 50, -10, 20, 30, 0, -100 },
|
|
{ -100, 0, 30, 20, -10, 50, -1 },
|
|
{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 },
|
|
{ -1, -2, -3, -4, -5, -6, -7, -8, -9, -10 },
|
|
{ 0, 0, 0, 0, 0, 0, 0, 0 }
|
|
};
|
|
|
|
printf("[TEST] Integer arrays\n");
|
|
for (size_t i = 0; i < examples_count; i++) {
|
|
size_t count = sizeof(examples[i]) / sizeof(int);
|
|
|
|
#ifdef DEBUG_OUTPUT
|
|
printf("Before sorting:");
|
|
print_numbers(examples[i], count);
|
|
putchar('\n');
|
|
#endif
|
|
|
|
select_sort(examples[i], count);
|
|
|
|
#ifdef DEBUG_OUTPUT
|
|
printf("After sorting:");
|
|
print_numbers(examples[i], count);
|
|
printf("\n\n");
|
|
#endif
|
|
|
|
check_if_sorted(examples[i], count);
|
|
}
|
|
printf("[PASS] Tests passed.\n\n");
|
|
}
|
|
// #pragma endregion TESTS
|
|
|
|
int main(void)
|
|
{
|
|
/* Neither of those tests check for bad behaviour, like overwriting array
|
|
* with elements satisfying ordering. **I** check those :scheming:
|
|
*/
|
|
check_int_arrays();
|
|
|
|
return 0;
|
|
}
|