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几种经典排序算法的C++实现

ai 2025/6/18 5:35:32

以下是几种经典排序算法的C++实现，包含冒泡排序、选择排序、插入排序、快速排序和归并排序：

#include <iostream>
#include <vector>
using namespace std;// 1. 冒泡排序
void bubbleSort(vector<int>& arr) {int n = arr.size();for (int i = 0; i < n-1; i++) {for (int j = 0; j < n-i-1; j++) {if (arr[j] > arr[j+1]) {swap(arr[j], arr[j+1]);}}}
}// 2. 选择排序
void selectionSort(vector<int>& arr) {int n = arr.size();for (int i = 0; i < n-1; i++) {int minIdx = i;for (int j = i+1; j < n; j++) {if (arr[j] < arr[minIdx]) {minIdx = j;}}swap(arr[i], arr[minIdx]);}
}// 3. 插入排序
void insertionSort(vector<int>& arr) {int n = arr.size();for (int i = 1; i < n; i++) {int key = arr[i];int j = i - 1;while (j >= 0 && arr[j] > key) {arr[j+1] = arr[j];j--;}arr[j+1] = key;}
}// 4. 快速排序
int partition(vector<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(vector<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);}
}// 5. 归并排序
void merge(vector<int>& arr, int left, int mid, int right) {int n1 = mid - left + 1;int n2 = right - mid;vector<int> L(n1), R(n2);for (int i = 0; i < n1; i++) {L[i] = arr[left + i];}for (int j = 0; j < n2; j++) {R[j] = arr[mid + 1 + j];}int i = 0, j = 0, k = left;while (i < n1 && j < n2) {if (L[i] <= R[j]) {arr[k] = L[i];i++;} else {arr[k] = R[j];j++;}k++;}while (i < n1) {arr[k] = L[i];i++;k++;}while (j < n2) {arr[k] = R[j];j++;k++;}
}void mergeSort(vector<int>& arr, int left, int right) {if (left < right) {int mid = left + (right - left) / 2;mergeSort(arr, left, mid);mergeSort(arr, mid+1, right);merge(arr, left, mid, right);}
}// 测试代码
int main() {vector<int> arr = {64, 25, 12, 22, 11};// 选择一种排序算法调用// bubbleSort(arr);// selectionSort(arr);// insertionSort(arr);// quickSort(arr, 0, arr.size()-1);mergeSort(arr, 0, arr.size()-1);cout << "排序后的数组: ";for (int num : arr) {cout << num << " ";}cout << endl;return 0;
}