排序算法

排序算法

sort.h

#pragma once
#include <iostream>
#include <vector>

using namespace std;

void BubbleSortPositive(std::vector<int> &nums);
void insertSortPositive(vector<int> &array);
void SelectionSort(vector<int> &nums);
void quickSort(vector<int> &nums, int left, int right);
void merge(vector<int> &nums, int left, int mid, int right);
void mergeSort(vector<int> &nums, int left, int right);
void heapSort(vector<int> &nums);
void heapify(vector<int> &nums, int n, int index);
void bucketSort(vector<int> &nums);
void bucketSortEX(vector<int> &nums);
void countSort(vector<int> &nums);
void shellSort(vector<int> &nums);
void radixSort(vector<int> &nums);

sort.cpp

#include "Sort.h"
#include <algorithm>

void BubbleSortPositive(std::vector<int> &nums)
{
    int cycle_index = nums.size();
    bool is_swap = false;
    for (int i = 1; i <= cycle_index; i++)
    {
        for (int j = 1; j <= cycle_index - i; j++)
        {
            if (nums[j] < nums[j - 1])
            {
                swap(nums[j], nums[j - 1]);
                is_swap = true;
            }
            bool check = true;
        }
        if (!is_swap)
            break;
    }
}

void insertSortPositive(vector<int> &array)
{
    int size = array.size();
    for (int i = 1; i < size; i++)
    {
        for (int j = i; j > 0 && array[j] < array[j - 1]; j--)
        {
            swap(array[j], array[j - 1]);
        }
    }
}

void SelectionSort(vector<int> &nums)
{
    int size = nums.size();
    for (int i = 0; i < size; i++)
    {
        int min = i;
        for (int j = i + 1; j < size; j++)
        {
            if (nums[j] < nums[min])
            {
                min = j;
            }
        }
        swap(nums[i], nums[min]);
    }
}

void quickSort(vector<int> &nums, int left, int right)

{
    if (left + 1 >= right)
        return;

    int piovt = nums[left];
    int low = left, higt = right;
    while (low < higt)
    {
        while (low < higt && nums[higt] >= piovt)
        {
            higt--;
        }
        nums[low] = nums[higt];
        while (low < higt && nums[low] <= piovt)
        {
            low++;
        }
        nums[higt] = nums[low];
    }
    nums[low] = piovt;
    quickSort(nums, left, low);
    quickSort(nums, ++low, right);
}

void merge(vector<int> &nums, int left, int mid, int right)
{
    // 取一个临时变量存储数据，为了使用方便，大小和原对象大小保持一致
    vector<int> temp(right + 1);

    // 取左右两份数据的两个索引，第一份数据从left到mid,第二份数据从mid+1到right
    int l = left;
    int r = mid + 1;
    // 取一个temp的索引从left开始，为了存数据
    int t = left;

    // 当左右的两个索引都没达到终点时，判断大小，小的就放入temp中
    while (l <= mid && r <= right)
    {
        if (nums[l] < nums[r])
        {
            temp[t++] = nums[l++];
        }
        else
        {
            temp[t++] = nums[r++];
        }
    }

    // 当左右的两个索引至少一个达到终点时，则把剩下一个容器的数据接着temp当前顺序存入数据
    while (l <= mid)
    {
        temp[t] = nums[l];
        t++;
        l++;
    }
    while (r <= right)
    {
        temp[t] = nums[r];
        t++;
        r++;
    }
    // 再把temp的从left到right到数据给到原对象
    for (int i = left; i <= right; i++)
    {
        nums[i] = temp[i];
    }
};
void mergeSort(vector<int> &nums, int left, int right)
{
    if (left >= right)
        return;
    int mid = (left + right) / 2;
    // 不断分为左右两份数据
    mergeSort(nums, left, mid);
    mergeSort(nums, mid + 1, right);
    // 分完后按从小到大的顺序合并两份数据，由于是递归，所以分到最小份的时候开始第一次合并，而最后一次合并则是第一次分离的数据
    merge(nums, left, mid, right);
};

void heapSort(vector<int> &nums)
{
    int size = nums.size();
    // 建堆
    for (int i = size / 2 - 1; i >= 0; i--)
    {
        heapify(nums, size, i);
    }
    // 排序
    for (int i = size - 1; i >= 0; i--)
    {
        swap(nums[i], nums[0]);
        heapify(nums, i, 0);
    }
};

void heapify(vector<int> &nums, int n, int index)
{
    int left = 2 * index + 1;
    int right = 2 * index + 2;
    int top = index;

    if (left < n && nums[left] > nums[top])
    {
        top = left;
    }
    if (right < n && nums[right] > nums[top])
    {
        top = right;
    }
    if (top != index)
    {
        swap(nums[index], nums[top]);
        heapify(nums, n, top);
    }
};

void bucketSort(vector<int> &nums)
{
    if (nums.empty())
        return;
    int low = *min_element(nums.begin(), nums.end());
    int high = *max_element(nums.begin(), nums.end());

    int n = high - low + 1;
    vector<int> bucket(n, 0);
    vector<int> res;

    for (auto &&x : nums)
    {
        ++bucket[x - low];
    }

    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < bucket[i]; j++)
        {
            res.push_back(i + low);
        }
    }

    nums = move(res);
};

void bucketSortEX(vector<int> &nums)
{
    int size = nums.size();
    int max = *max_element(nums.begin(), nums.end());
    int min = *min_element(nums.begin(), nums.end());
    int range = max - min;

    int bucketNum = (max - min) / range + 1;
    vector<vector<int>> bucketArray(bucketNum);

    for (auto &&value : nums)
    {
        int num = (value - min) / range;
        bucketArray[num].push_back(value);
    }

    for (int i = 0; i < bucketNum; i++)
    {
        quickSort(bucketArray[i], 0, bucketArray[i].size() - 1);
    }

    for (int i = bucketNum - 1; i > 0; i--)
    {
        bucketArray[i - 1].insert(bucketArray[i - 1].end(), bucketArray[i].begin(), bucketArray[i].end());
    }
    nums = move(bucketArray[0]);
};
void countSort(vector<int> &nums)
{
    /*
    1.判断原数据容量是否大于1
    2.获取原容器最大值
    3.根据原容器最大值，创建一个该大小的计数数组
    4.计数数组的数据，以索引为容器的数据值，以计数数组的数据也就是计数的数量值
    5.再把计数数组的数据从第二位数据开始，做累计（当前值=当前值+上一位的值）
    6.从以原数据容器的数据根据累计后的计数数组去查找需摆放的位置（计数数组每被取值一次则减一），存入与原数组同大小的数组中
    */
    if (nums.size() < 2)
        return;
    int max = *max_element(nums.begin(), nums.end());
    int min = *min_element(nums.begin(), nums.end());
    // 计数
    vector<int> countBox(max - min + 1, 0);

    for (auto &&i : nums)
    {
        countBox[i - min]++;
    }

    // 累计
    for (int i = 1; i < countBox.size(); i++)
    {
        countBox[i] += countBox[i - 1];
    }

    vector<int> temp(nums.size());

    for (size_t i = 0; i < nums.size(); i++)
    {
        temp[countBox[nums[i] - min] - 1] = nums[i];
        countBox[nums[i] - min]--;
    }

    nums = move(temp);
};

void shellSort(vector<int> &nums)
{
    int size = nums.size();
    for (int half = size / 2; half > 0; half /= 2)
    {
        for (int right = half; right < size; right++)
        {
            for (int left = right; left >= half; left -= half)
            {
                int compare = left - half;
                if (nums[left] < nums[compare])
                {
                    swap(nums[left], nums[compare]);
                }
            }
        }
    }
};

void radixSort(vector<int> &nums)
{
    const int radix = 10;
    int max = *max_element(nums.begin(), nums.end());
    int size = nums.size();
    int base = 1;
    while (max / base > 0)
    {
        vector<int> buckets(10);
        for (int i = 0; i < size; i++)
        {
            buckets[nums[i] / base % 10]++;
        }
        for (int i = 1; i < 10; i++)
        {
            buckets[i] += buckets[i - 1];
        }
        vector<int> temp(size, 0);
        for (int i = size - 1; i >= 0; i--)
        {
            temp[buckets[nums[i] / base % 10] - 1] = nums[i];
            buckets[nums[i] / base % 10]--;
        }
        nums = move(temp);
        base *= 10;
    }
}