cpp-algo-cases/chapter_sorting/quick_sort.cpp

/**
 * File: quick_sort.cpp
 * Created Time: 2022-11-25
 * Author: krahets (krahets@163.com)
 */

#include "../utils/common.hpp"

/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
class QuickSort {
  private:
    /* Ԫ<>ؽ<EFBFBD><D8BD><EFBFBD> */
    static void swap(vector<int> &nums, int i, int j) {
        int tmp = nums[i];
        nums[i] = nums[j];
        nums[j] = tmp;
    }

    /* <20>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD> */
    static int partition(vector<int> &nums, int left, int right) {
        // <20><> nums[left] Ϊ<><CEAA>׼<EFBFBD><D7BC>
        int i = left, j = right;
        while (i < j) {
            while (i < j && nums[j] >= nums[left])
                j--; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׸<EFBFBD>С<EFBFBD>ڻ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
            while (i < j && nums[i] <= nums[left])
                i++;          // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׸<EFBFBD><D7B8><EFBFBD><EFBFBD>ڻ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
            swap(nums, i, j); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
        }
        swap(nums, i, left); // <20><><EFBFBD><EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķֽ<C4B7><D6BD><EFBFBD>
        return i;            // <20><><EFBFBD>ػ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    }

  public:
    /* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    static void quickSort(vector<int> &nums, int left, int right) {
        // <20><><EFBFBD><EFBFBD><EFBFBD>鳤<EFBFBD><E9B3A4>Ϊ 1 ʱ<><CAB1>ֹ<EFBFBD>ݹ<EFBFBD>
        if (left >= right)
            return;
        // <20>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD>
        int pivot = partition(nums, left, right);
        // <20>ݹ<EFBFBD><DDB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>顢<EFBFBD><E9A1A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
        quickSort(nums, left, pivot - 1);
        quickSort(nums, pivot + 1, right);
    }
};

/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ࣨ<EFBFBD><E0A3A8>λ<EFBFBD><CEBB>׼<EFBFBD><D7BC><EFBFBD>Ż<EFBFBD><C5BB><EFBFBD> */
class QuickSortMedian {
  private:
    /* Ԫ<>ؽ<EFBFBD><D8BD><EFBFBD> */
    static void swap(vector<int> &nums, int i, int j) {
        int tmp = nums[i];
        nums[i] = nums[j];
        nums[j] = tmp;
    }

    /* ѡȡ<D1A1><C8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѡԪ<D1A1>ص<EFBFBD><D8B5><EFBFBD>λ<EFBFBD><CEBB> */
    static int medianThree(vector<int> &nums, int left, int mid, int right) {
        // <20>˴<EFBFBD>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>򻯴<EFBFBD><F2BBAFB4><EFBFBD>
        // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 0 ^ 0 = 1 ^ 1 = 0, 0 ^ 1 = 1 ^ 0 = 1
        if ((nums[left] < nums[mid]) ^ (nums[left] < nums[right]))
            return left;
        else if ((nums[mid] < nums[left]) ^ (nums[mid] < nums[right]))
            return mid;
        else
            return right;
    }

    /* <20>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD>֣<EFBFBD><D6A3><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1>ֵ<EFBFBD><D6B5> */
    static int partition(vector<int> &nums, int left, int right) {
        // ѡȡ<D1A1><C8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѡԪ<D1A1>ص<EFBFBD><D8B5><EFBFBD>λ<EFBFBD><CEBB>
        int med = medianThree(nums, left, (left + right) / 2, right);
        // <20><><EFBFBD><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
        swap(nums, left, med);
        // <20><> nums[left] Ϊ<><CEAA>׼<EFBFBD><D7BC>
        int i = left, j = right;
        while (i < j) {
            while (i < j && nums[j] >= nums[left])
                j--; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׸<EFBFBD>С<EFBFBD>ڻ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
            while (i < j && nums[i] <= nums[left])
                i++;          // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׸<EFBFBD><D7B8><EFBFBD><EFBFBD>ڻ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
            swap(nums, i, j); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
        }
        swap(nums, i, left); // <20><><EFBFBD><EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķֽ<C4B7><D6BD><EFBFBD>
        return i;            // <20><><EFBFBD>ػ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    }

  public:
    /* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    static void quickSort(vector<int> &nums, int left, int right) {
        // <20><><EFBFBD><EFBFBD><EFBFBD>鳤<EFBFBD><E9B3A4>Ϊ 1 ʱ<><CAB1>ֹ<EFBFBD>ݹ<EFBFBD>
        if (left >= right)
            return;
        // <20>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD>
        int pivot = partition(nums, left, right);
        // <20>ݹ<EFBFBD><DDB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>顢<EFBFBD><E9A1A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
        quickSort(nums, left, pivot - 1);
        quickSort(nums, pivot + 1, right);
    }
};

/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ࣨβ<E0A3A8>ݹ<EFBFBD><DDB9>Ż<EFBFBD><C5BB><EFBFBD> */
class QuickSortTailCall {
  private:
    /* Ԫ<>ؽ<EFBFBD><D8BD><EFBFBD> */
    static void swap(vector<int> &nums, int i, int j) {
        int tmp = nums[i];
        nums[i] = nums[j];
        nums[j] = tmp;
    }

    /* <20>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD> */
    static int partition(vector<int> &nums, int left, int right) {
        // <20><> nums[left] Ϊ<><CEAA>׼<EFBFBD><D7BC>
        int i = left, j = right;
        while (i < j) {
            while (i < j && nums[j] >= nums[left])
                j--; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׸<EFBFBD>С<EFBFBD>ڻ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
            while (i < j && nums[i] <= nums[left])
                i++;          // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׸<EFBFBD><D7B8><EFBFBD><EFBFBD>ڻ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
            swap(nums, i, j); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
        }
        swap(nums, i, left); // <20><><EFBFBD><EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķֽ<C4B7><D6BD><EFBFBD>
        return i;            // <20><><EFBFBD>ػ<EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    }

  public:
    /* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>β<EFBFBD>ݹ<EFBFBD><DDB9>Ż<EFBFBD><C5BB><EFBFBD> */
    static void quickSort(vector<int> &nums, int left, int right) {
        // <20><><EFBFBD><EFBFBD><EFBFBD>鳤<EFBFBD><E9B3A4>Ϊ 1 ʱ<><CAB1>ֹ
        while (left < right) {
            // <20>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD>ֲ<EFBFBD><D6B2><EFBFBD>
            int pivot = partition(nums, left, right);
            // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>н϶̵<CFB6><CCB5>Ǹ<EFBFBD>ִ<EFBFBD>п<EFBFBD><D0BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
            if (pivot - left < right - pivot) {
                quickSort(nums, left, pivot - 1); // <20>ݹ<EFBFBD><DDB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
                left = pivot + 1;                 // ʣ<><CAA3>δ<EFBFBD><CEB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ [pivot + 1, right]
            } else {
                quickSort(nums, pivot + 1, right); // <20>ݹ<EFBFBD><DDB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
                right = pivot - 1;                 // ʣ<><CAA3>δ<EFBFBD><CEB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ [left, pivot - 1]
            }
        }
    }
};

/* Driver Code */
int main() {
    /* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
    vector<int> nums{2, 4, 1, 0, 3, 5};
    QuickSort::quickSort(nums, 0, nums.size() - 1);
    cout << "<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɺ<EFBFBD> nums = ";
    printVector(nums);

    /* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><CEBB>׼<EFBFBD><D7BC><EFBFBD>Ż<EFBFBD><C5BB><EFBFBD> */
    vector<int> nums1 = {2, 4, 1, 0, 3, 5};
    QuickSortMedian::quickSort(nums1, 0, nums1.size() - 1);
    cout << "<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD>׼<EFBFBD><EFBFBD><EFBFBD>Ż<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɺ<EFBFBD> nums = ";
    printVector(nums);

    /* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>β<EFBFBD>ݹ<EFBFBD><DDB9>Ż<EFBFBD><C5BB><EFBFBD> */
    vector<int> nums2 = {2, 4, 1, 0, 3, 5};
    QuickSortTailCall::quickSort(nums2, 0, nums2.size() - 1);
    cout << "<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>β<EFBFBD>ݹ<EFBFBD><EFBFBD>Ż<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɺ<EFBFBD> nums = ";
    printVector(nums);

    return 0;
}