排序

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#include<iostream>#include<cstdio>#define INF 999999#define MAXSIZE 20using namespace std;//选择排序、快速排序、希尔排序、堆排序不是稳定的排序算法//冒泡排序、插入排序、归并排序和基数排序都是稳定的排序算法。//直接插入排序，最好o(n),最差o(n^2)平均时间复杂度：o(n^2)，空间复杂度 o(1)void InserSort(int*a, int n){    for (int i = 1; i<n; i++){        int j = i - 1, temp = a[i];        while (j >= 0 && temp<a[j]){            a[j + 1] = a[j];            j--;        }        a[j + 1] = temp;    }}//获得排好的数组序void getOrder(int* a, int n){    for (int i = 0; i<n; i++){        printf("%d ", a[i]);    }    printf("\n");}//还原序列，方便下次测void backOrder(int* a, int n){    for (int i = 0; i<n; i++)a[i] = n - i;}//折半插入排序,最好情况o(nlogn) ,最差情况o(n^2),空间复杂度o(1)void binaySort(int* a, int n){    for (int i = 1; i<n; i++){        int left = 0, right = i - 1;        while (left<right){            int mid = (left + right) / 2;            if (a[i] >= a[mid])left = mid + 1;            else right = mid - 1;        }        int limit = a[i] >= a[left] ? left + 1 : left, temp = a[i];        for (int k = i - 1; k >= 0; k--)a[k + 1] = a[k];        a[limit] = temp;    }}//最坏时间复杂度 o(n^2), 最好时间复杂度o(n),平均时间复杂度o(n^2),空间复杂度o(1)void BubbleSort(int *a, int n){    int i, j, flag;    for (int i = 0; i<n - 1; i++){        flag = 0;        for (int k = 0; k<n - i - 1; k++){            if (a[k]>a[k + 1]){                int t = a[k + 1];                a[k + 1] = a[k];                a[k] = t;                flag = 1;            }        }        if (!flag)break;    }}//时间复杂度nlog2^n ，越接近无序时间复杂度越低，反之越高，空间复杂度为log2^nvoid QuickSort(int* a, int left, int right){    if (left<right){        int x = left, y = right, temp = a[left];        while (x<y){            while (x<y&&a[y] >= temp)y--;            a[x] = a[y];            while (x<y&&a[x] <= temp)x++;            a[y] = a[x];        }        a[x] = temp;        QuickSort(a, left, x - 1);        QuickSort(a, x + 1, right);    }}//时间复杂度o(n^2) ,空间复杂度o(1)void SelectSort(int* a, int n){    for (int i = 0; i<n - 1; i++){        int min = i, t;        for (int k = i; k<n; k++){            if (a[k]<a[min])min = k;        }        t = a[i];        a[i] = a[min];        a[min] = t;    }}//堆调整void heapAdjust(int*a, int s, int m){    int temp = a[s];    cout << "a[s]==" << a[s] << endl;    for (int j = s * 2; j <= m; j *= 2){        if (j<m&&a[j + 1]>a[j]){            j++;        }        if (temp >= a[j]){            break;//说明该节点本来就比左右子树大        }        a[s] = a[j];        s = j;                //s指向交换后空的位置    }    a[s] = temp;}//堆排序, headAjust log2^n, 第一个循环(n/2)*log2^n, 第二个循环 n*log2^n 故该算法的时间复杂度为n*lpg2^n void HeapSort(int* a, int n){    for (int i = n / 2; i >= 1; i--){        heapAdjust(a, i, n);    }    for (int i = n; i >= 1; i--){        int temp = a[1];        a[1] = a[i];        a[i] = temp;        heapAdjust(a, 1, i - 1);    }}void merge(int* a, int* b, int* c ,int left,int middle,int right){    int cnt = left,i=left,j=middle+1;    while (i <=middle&&j <= right){        if (a[i] < b[j]){            c[cnt] = a[i++];        }        else{            c[cnt] = b[j++];        }        cnt++;    }    if (i <= middle)while(i<=middle){        c[cnt] = a[i];        i++;        cnt++;    }    if (j <= right)while(j<=right){        c[cnt] = b[j];        j++;        cnt++;    }}//对a,数组[left..right]合并排序到b ，时间复杂度o(nlogn^2),空间复杂度o(n)void mergeSort(int*a, int* b, int left, int right){    if (left == right){        b[left] = a[right];    }    else{        int middle = (left + right) / 2, temp1[MAXSIZE], temp2[MAXSIZE];        mergeSort(a, temp1, left, middle);        mergeSort(a, temp2, middle + 1, right);        merge(temp1,temp2,b,left,middle,right);    }}int main(){    int a[] = { 0, 10, 9, 8, 7 };    mergeSort(a, a, 1, 4);    for (int i = 1; i <= 4; i++)cout << a[i] << " ";    cout << endl;    cout << endl;    system("pause");    return 0;}
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