冒泡、选择、插入、归并、快速排序代码

原理请查看：http://wuchong.me/blog/2014/02/09/algorithm-sort-summary/

冒泡排序

void bubble_sort(int * array, int len){    int tmp;    for (int i=0; i<len; ++i)    {        for (int j=0; j<(len-i-1); ++j)        {            if(array[j+1] < array[j])            {                //tmp = array[j+1];                //array[j+1] = array[j];                //array[j] = tmp;                swap(array[j+1], array[j]);            }        }    }}

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选择排序

void selection_sort(int * array, int len){    int tmp;    int k = 0;    for (int i=0; i<len; ++i)//从第一个数值开始遍历    {        k = i;        tmp = array[i];        for (int j=i+1; j<len; ++j)//循环找出最小数值        {            if (tmp > array[j])            {                tmp = array[j];                k = j;            }        }        if (i != k)//有找到最小数值，则数据进行交换        {            //array[k] = array[i];            //array[i] = tmp;            swap(array[k], array[i]);        }    }}

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插入排序

void insertion_sort(int * array, int len){    int tmp;    for (int i=1;i<len;++i)//插入数值遍历    {        tmp = array[i];        for (int j=i-1;j>=0;--j)//以自己一下的数值一个一个比较        {            if (array[j] <= tmp)//当比自己大于或等于数据，则插入这个数值前面            {                array[j+1] = tmp;                break;            }            else//当比自己小数值，则将数值向前移动一位            {                array[j+1] = array[j];            }            if(0 == j)//如果比较到最后一个，直接插入自己值。            {                array[j] = tmp;            }        }    }}

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归并排序

void Merge(int *vi, int low, int mid, int up){#if 0    int n1 = mid-low+1;    int n2 = up-mid;#else    int n1 = mid-low;    int n2 = up-mid+1;#endif    int *L = new int[n1+1];    int *R = new int[n2+1];    int i, j, k;//  for (i=0; i<n1; i++){//      L[i] = vi[low+i];//  }//  for (j=0; j<n2; j++){//      R[j] = vi[mid+j+1];//  }#if 0    memcpy(L, &vi[low], n1*sizeof(int));    L[n1] = 0x7fffffff;    memcpy(R, &vi[mid+1], n2*sizeof(int));    R[n2] = 0x7fffffff;#else    memcpy(L, &vi[low], n1*sizeof(int));    L[n1] = 0x7fffffff;    memcpy(R, &vi[mid], n2*sizeof(int));    R[n2] = 0x7fffffff;#endif    for (i=0, j=0, k=low; k<=up; k++)    {        if (L[i]<=R[j])        {            vi[k] = L[i];            i++;        }        else        {            vi[k] = R[j];            j++;        }    }    delete []L;    delete []R;}void MergeSort(int *vi, int low, int up){    if (low < up)    {        int mid = (low+up)/2;        MergeSort(vi, low, mid);        MergeSort(vi, mid+1, up);        Merge(vi, low, mid, up);    }}int main(){    int array[] = {2,8,7,1,0,10,3};    int len = sizeof(array);    MergeSort(array, 0, len-1);    return 0;}

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快速排序

int partition(int * vi, int low, int up){    int pivot = vi[up];    int i = low;    for (int j = low; j < up; j++)    {        if(vi[j] <= pivot)        {            swap(vi[i], vi[j]);            i++;        }    }    swap(vi[i], vi[up]);//交换位置，防止同一个位置做基准    return i;}//C++'s array range should be [low, up], the same as [low, up+1)void quickSort(int * vi, int low, int up){    if(low < up)    {        int mid = partition(vi, low, up);        //mid这个值已经做为基准了，所以后面用mid-1和mid+1;        //Watch out! The mid position is on the place, so we don't need to consider it again.        //That's why below is mid-1, not mid! Otherwise it will occur overflow error!!!        quickSort(vi, low, mid-1);        quickSort(vi, mid+1, up);    }}int main(){    int array[] = {2,8,7,1,0,10,3};    int len = sizeof(array);    quickSort(array, 0, len-1);    return 0;}