HDOJ 2020 绝对值排序

        简单的排序题目，只是要注意是对数的绝对值进行排序。我这采用的是插入排序+随机化快速排序进行排序(只使用随机化快排的话，函数递归的深度有点吓人，为了减小递归的深度，在对少量元素进行排序的时候采用插入排序)。直接使用C/C++标准库提供的排序方法其实还比较麻烦。其实像这样不是很繁琐的基础算法，最好是自己重新写，也算是加深印象吧。

#include <cstdio>#include <cstdlib>#include <ctime>void quickSort(int[], int, int);int partition(int[], int, int);void insertionSort(int[], int, int);void exchange(int &, int &);int data[100 + 5];//#define yangyuanint main(){#ifdef yangyuanfreopen("in", "r", stdin);#endif // yangyuansrand(time(NULL));    int n;    while (scanf("%d", &n) != EOF){if (0 == n)break;for (int i = 0; i < n; i++)scanf("%d", data + i);quickSort(data, 0, n - 1);for (int i = 0; i < n; i++){printf("%d", data[i]);if (i != n - 1)printf(" ");}printf("\n");}    return 0;}void quickSort(int data[], int low, int high){    if (low < high){        if (high - low > 10){int mid = partition(data, low, high);quickSort(data, low, mid - 1);quickSort(data, mid + 1, high);}else            insertionSort(data, low, high);}}int partition(int data[], int low, int high){int randIndex = rand() % (high - low + 1) + low;    exchange(data[randIndex], data[high]);    int i = low, absKey = data[high] < 0 ? -data[high] : data[high];    for (int j = low; j < high; j++){if ((data[j] < 0 ? -data[j] : data[j]) > absKey)// 注意，这个排序依据的是绝对值的大小{if (i != j)exchange(data[i], data[j]);            i++;}}    exchange(data[i], data[high]);    return i;}inline void exchange(int &a, int &b){    int temp = a;    a = b;    b = temp;}void insertionSort(int data[], int low, int high){    for (int i = low + 1; i <= high; i++){        int key = data[i], j = i - 1;        int absKey = key < 0 ? -key : key;        for (; j >= low && absKey > (data[j] < 0 ? -data[j] : data[j]); j--)// 注意，这个排序依据的是绝对值的大小            data[j + 1] = data[j];data[j + 1] = key;}}