常用排序算法C++实现（堆排序，快速排序，归并排序，基数排序）

来源：互联网发布：淘宝的运营模式是编辑：程序博客网时间：2024/06/07 10:29
#include <iostream>#include <cstdlib>#include <ctime>#include <algorithm>using namespace std;const int ARR_COUNT = 5;const int SIZE = 18;const int RANGE = 1000;int arr[6][SIZE];/** heapSort, quickSort, mergeSort, radixSort*//** common*/void mySwap(int& a, int&b) {int temp = a;a = b;b = temp;}void printArr(const int arr[], const int size) {cout << "[ ";for (int i = 0; i < size; ++i) cout << arr[i] << " ";cout << "]" << endl;}/* * heap sort */void balanceMaxHeap(int arr[], const int i, const int size) {if (i * 2 < size) { //has childint maxValIndex = i;if (arr[i * 2] > arr[maxValIndex]) maxValIndex = i * 2;if (i * 2 + 1 < size && arr[i * 2 + 1] > arr[maxValIndex]) maxValIndex = i * 2 + 1;if (maxValIndex != i) {mySwap(arr[i], arr[maxValIndex]);balanceMaxHeap(arr, maxValIndex, size);}}}void buildMaxHeap(int arr[], const int size) {for (int i = size - 1; i >= 0; --i) { //build heapbalanceMaxHeap(arr, i, size);}}void heapSort(int arr[], const int size) {buildMaxHeap(arr, size);for (int i = 0; i < size; ++i) { //popmySwap(arr[0], arr[size - 1 - i]);balanceMaxHeap(arr, 0, size - 1 - i);}}/** quick sort*/int partition(int arr[], const int start, const int end) {int i = start + rand() * (end - start) / (RAND_MAX + 1);mySwap(arr[i], arr[end - 1]); //swap with last elementint pos = start;for (int i = start; i < end - 1; ++i) {if (arr[i] < arr[end - 1]) mySwap(arr[pos++], arr[i]);}mySwap(arr[pos], arr[end - 1]);return pos;}void quickSortCore(int arr[], const int start, const int end) { //[start, end)if (start + 1 < end) { //at least two elementsint mid = partition(arr, start, end);quickSortCore(arr, start, mid);quickSortCore(arr, mid + 1, end);}}void quickSort(int arr[], const int size) {quickSortCore(arr, 0, size);}/** merge sort*/void mergeSortCore(int arr[], const int start, const int end) { //[start, end)if (start + 1 < end) { //at least two elementsint mid = start + (end - start) / 2;mergeSortCore(arr, start, mid);mergeSortCore(arr, mid, end);//mergeint start1 = start, start2 = mid;int* mergeArr = new int[end - start];int mergeArrStart = 0;while (start1 < mid && start2 < end) {if (arr[start1] <= arr[start2]) mergeArr[mergeArrStart++] = arr[start1++];else mergeArr[mergeArrStart++] = arr[start2++];}while (start1 < mid) mergeArr[mergeArrStart++] = arr[start1++];while (start2 < end) mergeArr[mergeArrStart++] = arr[start2++];memcpy(arr + start, mergeArr, sizeof(int) * (end - start));delete[] mergeArr;}}void mergeSort(int arr[], const int size) {mergeSortCore(arr, 0, size);}/** radix sort, only effective for uint32_t*/void radixSortCore(int arr[], int temp[], const int size, const int offset) {const int mask = 0xFF;int cnt[256] = { 0 };for (int i = 0; i < size; ++i) cnt[(arr[i] >> offset) & mask]++;for (int i = 1; i < 256; ++i) cnt[i] += cnt[i - 1];for (int i = size - 1; i >= 0; --i) temp[--cnt[(arr[i] >> offset) & mask]] = arr[i];}void radixSort(int arr[], const int size) {int* temp = new int[size];radixSortCore(arr, temp, size, 0);radixSortCore(temp, arr, size, 8);radixSortCore(arr, temp, size, 16);radixSortCore(temp, arr, size, 24);delete[] temp;}int main(){srand((unsigned int)time(NULL));for (int i = 0; i < SIZE; ++i) arr[0][i] = rand() * RANGE / (RAND_MAX + 1);for (int i = 1; i < ARR_COUNT; ++i) memcpy(arr[i], arr[0], sizeof(arr[0]));cout << "Original array:" << endl;for (int i = 0; i < ARR_COUNT; ++i) printArr(arr[i], SIZE);sort(arr[0], arr[0] + SIZE);heapSort(arr[1], SIZE);quickSort(arr[2], SIZE);mergeSort(arr[3], SIZE);radixSort(arr[4], SIZE);cout << "After sorting:" << endl;for (int i = 0; i < ARR_COUNT; ++i) printArr(arr[i], SIZE);return 0;}
0 0