C语言学习： 案例： 指针版本的快速排序
1 #include <stdio.h> 2 #include "io_utils.h" 3 #include <stdlib.h> 4 #include <time.h> 5 6 void SwapInt(int *a, int *b) { 7 int temp = *a; 8 *a = *b; 9 *b = temp; 10 } 11 12 void Shuffle(int *array, int length) { 13 srand(time(NULL)); 14 15 for (int i = length - 1; i > 0; --i) { 16 int random_number = rand() % i; 17 SwapInt(array + i, array + random_number); 18 } 19 } 20 21 int *Partition(int *low, int *high) { 22 int pivot = *(low + (high - low) / 2); 23 int *p = low; 24 int *q = high; 25 26 while (1) { 27 while (*p < pivot) p++; 28 while (*q > pivot) q--; 29 30 if (p >= q) break; 31 SwapInt(p, q); 32 } 33 34 return q; 35 } 36 37 void QuickSort(int *low, int *high) { 38 if (low >= high) return; 39 int *partition = Partition(low, high); 40 QuickSort(low, partition - 1); 41 QuickSort(partition + 1, high); 42 } 43 44 #define PLAYER_COUNT 10 45 46 int main() { 47 int *players = malloc(sizeof(int) * PLAYER_COUNT); 48 if (!players) { 49 return 1; 50 } 51 for (int i = 0; i < PLAYER_COUNT; ++i) { 52 players[i] = i; 53 } 54 Shuffle(players, PLAYER_COUNT); 55 PRINT_INT_ARRAY(players, PLAYER_COUNT); 56 QuickSort(players, players + PLAYER_COUNT - 1); 57 PRINT_INT_ARRAY(players, PLAYER_COUNT); 58 free(players); 59 60 return 0; 61 }
