排序算法(C++)

来源：互联网发布：windows udp 编辑：程序博客网时间：2024/06/01 10:14
原文出处:排序算法总结
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#include "stdafx.h"#include <iostream>#include <time.h>using namespace std;/**1. 冒泡排序*///时间复杂度为O(N ^ 2)，空间复杂度为O(1)。排序是稳定的void bubble_sort(int arr[], int len){    //每次从后往前冒一个最小值，且每次能确定一个数在序列中的最终位置    for (int i = 0; i < len - 1; i++){         //比较n-1次        bool exchange = true;               //冒泡的改进，若在一趟中没有发生逆序，则该序列已有序        for (int j = len - 1; j >i; j--){    // 每次从后边冒出一个最小值            if (arr[j] < arr[j - 1]){       //发生逆序，则交换                swap(arr[j], arr[j - 1]);                exchange = false;            }        }        if (exchange){            return;        }    }}/**2. 插入排序*///时间复杂度为O(N^2)，空间复杂度为O(1)。算法是稳定的void insert_sort(int arr[], int len){    //每次把当前的数往前插入，可以顺序插入，改进的可以进行二分插入    for (int i = 1; i < len; i++){        if (arr[i] < arr[i - 1]){      //发生逆序，往前插入            int temp = arr[i];            int j;            for (j = i - 1; j >= 0 && arr[j]>temp; j--){                arr[j + 1] = arr[j];            }            arr[j + 1] = temp;        }    }}void insert_binary_sort(int arr[], int len){    //改进的插入排序，往前插入比较时，进行二分查找    for (int i = 1; i < len; i++){        if (arr[i] < arr[i - 1]){            int temp = arr[i];            int low = 0, high = i - 1, mid;            while (low <= high){                mid = (low + high) / 2;                if (temp < arr[mid]){                    high = mid - 1;                }                else{                    low = mid + 1;                }            }            for (int j = i; j >low; j--){                arr[j] = arr[j - 1];            }            arr[low] = temp;        }    }}/**3. 希尔排序*/void shell_sort(int arr[], int len){    //每次选择一个gap，对相隔gap的数进行插入排序    for (int gap = len / 2; gap > 0; gap /= 2){        for (int i = 0; i < len; i = i + gap){            int temp = arr[i];            int j;            for (j = i; j >= gap && temp < arr[j - gap]; j -= gap){                arr[j] = arr[j - gap];            }            arr[j] = temp;        }    }}/**4. 选择排序*/void select_sort(int arr[], int len){    //每次从后边选择一个最小值    for (int i = 0; i < len - 1; i++){     //只需选择n-1次        int min = i;        for (int j = i + 1; j < len; j++){            if (arr[min]>arr[j]){                min = j;            }        }        if (min != i){            swap(arr[i], arr[min]);        }    }}/**5. 快速排序*///快速排序int partition(int arr[], const int left, const int right){    //对序列进行划分，以第一个为基准    int pivot = arr[left];    int pivotpos = left;    for (int i = left + 1; i <= right; i++){        if (arr[i] < pivot){            pivotpos++;            if (pivotpos != i){     //如果交换元素就位于基准后第一个，则不需要交换                swap(arr[i], arr[pivotpos]);            }        }    }    arr[left] = arr[pivotpos];    arr[pivotpos] = pivot;    return pivotpos;}void quick_sort(int arr[], const int left, const int right){    if (left < right){        int pivotpos = partition(arr, left, right);        quick_sort(arr, left, pivotpos - 1);        quick_sort(arr, pivotpos + 1, right);    }}void quick_sort(int arr[], int len){    quick_sort(arr, 0, len - 1);}int improve_partition(int arr[], int left, int right){    //基准进行随机化处理    int n = right - left + 1;    srand(time((unsigned)0));    int gap = rand() % n;    swap(arr[left], arr[left + gap]);  //把随机化的基准与左边进行交换    //再从左边开始进行    return partition(arr, left, right);}void quick_improve_sort(int arr[], const int left, const int right){    //改进的快速排序    //改进的地方：1、在规模较小时采用插入排序    //2、基准进行随机选择    int M = 5;    if (right - left < M){        insert_sort(arr, right - left + 2);    }    if (left >= right){        return;    }    int pivotpos = improve_partition(arr, left, right);    quick_improve_sort(arr, left, pivotpos - 1);    quick_improve_sort(arr, pivotpos + 1, right);}void quick_improve_sort(int arr[], int len){    quick_improve_sort(arr, 0, len - 1);}/**6. 归并排序*///归并排序void merge(int arr[], int temp_arr[], int left, int mid, int right){    //简单归并：先复制到temp_arr，再进行归并    for (int i = left; i <= right; i++){        temp_arr[i] = arr[i];    }    int pa = left, pb = mid + 1;    int index = left;    while (pa <= mid && pb <= right){        if (temp_arr[pa] <= temp_arr[pb]){            arr[index++] = temp_arr[pa++];        }        else{            arr[index++] = temp_arr[pb++];        }    }    while (pa <= mid){        arr[index++] = temp_arr[pa++];    }    while (pb <= right){        arr[index++] = temp_arr[pb++];    }}void merge_improve(int arr[], int temp_arr[], int left, int mid, int right){    //优化归并：复制时，俩头小，中间大，一次比较完    for (int i = left; i <= mid; i++){        temp_arr[i] = arr[i];    }    for (int i = mid + 1; i <= right; i++){        temp_arr[i] = arr[right + mid + 1 - i];    }    int pa = left, pb = right, p = left;    while (p <= right){        if (temp_arr[pa] <= temp_arr[pb]){            arr[p++] = temp_arr[pa++];        }        else{            arr[p++] = temp_arr[pb--];        }    }}void merge_sort(int arr[], int temp_arr[], int left, int right){    if (left < right){        int mid = (left + right) / 2;        merge_sort(arr, temp_arr, 0, mid);        merge_sort(arr, temp_arr, mid + 1, right);        merge(arr, temp_arr, left, mid, right);    }}void merge_sort(int arr[], int len){    int *temp_arr = (int*)malloc(sizeof(int)*len);    merge_sort(arr, temp_arr, 0, len - 1);}/**7. 堆排序*/void shiftDown(int arr[], int start, int end){    //从start出发到end，调整为最大堆    int dad = start;    int son = dad * 2 + 1;    while (son <= end){        //先选取子节点中较大的        if (son + 1 <= end && arr[son] < arr[son + 1]){            son++;        }        //若子节点比父节点大，则交换，继续往子节点寻找；否则退出        if (arr[dad] < arr[son]){            swap(arr[dad], arr[son]);            dad = son;            son = dad * 2 + 1;        }        else{            break;        }    }}void heap_sort(int arr[], int len){    //先调整为最大堆，再依次与第一个交换，进行调整，最后构成最小堆    for (int i = (len - 2) / 2; i >= 0; i--){   //len为总长度，最后一个为len-1,所以父节点为    (len-1-1)/2        shiftDown(arr, i, len - 1);    }    for (int i = len - 1; i >= 0; i--){        swap(arr[i], arr[0]);        shiftDown(arr, 0, i - 1);    }}/**8. 基数排序*/int maxbit(int data[], int n){    int d = 1;    for (int i = 0; i<n; i++)    {        int c = 1;        int p = data[i];        while (p / 10)        {            p = p / 10;            c++;        }        if (c>d)            d = c;    }    return d;}void RadixSort(int data[], int n){    int count[10];    int tmp[10];    int d = maxbit(data, n);    int r = 1;    for (int i = 0; i<d; i++)    {        for (int i = 0; i<10; i++)//装桶之前要先清桶            count[i] = 0;        for (i = 0; i<n; i++) //记录每个桶的记录数        {            int k = data[i] / r;            int q = k % 10;            count[q]++;        }        for (i = 1; i<10; i++)//计算位置        {            count[i] += count[i - 1];            //cout<<count[i]<<" ";        }        for (int j = n - 1; j >= 0; j--)        {            int p = data[j] / r;            int s = p % 10;            tmp[count[s] - 1] = data[j];            count[s]--;            //cout<<data[j]<<" ";        }        for (i = 0; i<n; i++)        {            data[i] = tmp[i];            //cout<<tmp[i]<<" ";        }        //    cout<<endl;        r = r * 10;    }}int main(){    int arr[] = { 1, 3, 5, 4, 2, 1, 9,19,18,17,16,19};    int len = 7;    for (int i = 0; i < len; i++){        cout << arr[i] << " ";    }    cout << endl;    RadixSort(arr, len);    for (int i = 0; i < len; i++){        cout << arr[i] << " ";    }    system("pause");    return 0;}
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