快速排序
用顺序映像实现快速排序算法,具体要求:
(1).在主函数中用rand()函数(需包含“stdlib.h”头文件)产生100000个随机数([0~10000)之间),并输出这100000个数。然后调用函数fun()进行快速排序;
(2).在fun函数中,按快速排序算法进行排序;
(3)在主函数中输出排好序后的数据
#include <stdio.h>
#include <stdlib.h>
void swap(int *a, int *b) {
int temp = *a;
*a = *b;
*b = temp;
}
int partition(int arr[], int low, int high) {
int pivot = arr[high];
int i = low - 1;
for (int j = low; j < high; j++) {
if (arr[j] <= pivot) {
i++;
swap(&arr[i], &arr[j]);
}
}
swap(&arr[i + 1], &arr[high]);
return i + 1;
}
void quickSort(int arr[], int low, int high) {
if (low < high) {
int pi = partition(arr, low, high);
quickSort(arr, low, pi - 1);
quickSort(arr, pi + 1, high);
}
}
void fun(int arr[], int n) {
quickSort(arr, 0, n - 1);
}
int main() {
int n = 100000;
int arr[n];
for (int i = 0; i < n; i++) {
arr[i] = rand() % 10001;
}
printf("Before sorting:\n");
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
fun(arr, n);
printf("After sorting:\n");
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
return 0;
}
可以参考下面的代码:
#include <stdio.h>
#include <stdlib.h>
void swap(int *a, int *b) {
int temp = *a;
*a = *b;
*b = temp;
}
int partition(int arr[], int low, int high) {
int pivot = arr[high];
int i = low - 1;
for (int j = low; j < high; j++) {
if (arr[j] <= pivot) {
i++;
swap(&arr[i], &arr[j]);
}
}
swap(&arr[i + 1], &arr[high]);
return i + 1;
}
void quickSort(int arr[], int low, int high) {
if (low < high) {
int pivotIndex = partition(arr, low, high);
quickSort(arr, low, pivotIndex - 1);
quickSort(arr, pivotIndex + 1, high);
}
}
void fun(int arr[], int n) {
quickSort(arr, 0, n - 1);
}
int main() {
int n = 100000;
int arr[n];
for (int i = 0; i < n; i++) {
arr[i] = rand() % 10001;
printf("%d ", arr[i]);
}
printf("\n");
fun(arr, n);
for (int i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
return 0;
}