个人手撕代码一、排序相关
相关链接：
C++十种排序方法（快速排序、冒泡排序等等）_超威蓝猫的哥哥的博客-CSDN博客_c++排序方法有哪几种
六大排序算法：插入排序、希尔排序、选择排序、冒泡排序、堆排序、快速排序_双鱼211的博客-CSDN博客
以下交换值可以均改用swap，懒得改了
一、冒泡排序
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void BubbleSort(vector& vec)
{
int n=vec.size();
if (n == 0)
return;
for (int i = 0; i < n; ++i)
{
for (int j = i; j < n; ++j)
{
if (vec[i] > vec[j])
{
int tmp = vec[j];
vec[j] = vec[i];
vec[i] = tmp;
}
}
}
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
BubbleSort(vec);
PrintVec(vec);
std::cout << "Hello World!\n";
}
二、选择排序
每次外循环选择剩余最小排好。
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void ChooseSort(vector& vec)
{
int n=vec.size();
if (n == 0)
return;
for (int i = 0; i < n-1; ++i)
{
int smallest = i;
for (int j = i+1; j < n; ++j)
{
if (vec[j] < vec[smallest])
{
smallest = j;
}
}
int tmp = vec[i];
vec[i] = vec[smallest];
vec[smallest] = tmp;
}
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
ChooseSort(vec);
PrintVec(vec);
std::cout << "Hello World!\n";
}
三、插入排序
十大经典排序算法之插入排序（Insertion Sort）_bfhonor的博客-CSDN博客_插入排序
插入排序详解_云杉木屋的博客-CSDN博客_插入排序
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void InsertSort(vector& vec)
{
int n=vec.size();
if (n == 0)
return;
for (int i = 1; i < n; ++i)
{
for (int j = i; j >=1; --j)
{
if (vec[j-1] > vec[j])
{
int tmp = vec[j-1];
vec[j-1] = vec[j];
vec[j] = tmp;
}
}
}
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
InsertSort(vec);
PrintVec(vec);
std::cout << "Hello World!\n";
}
四、希尔排序
排序——希尔排序（Shell's sort）_努力的老周的博客-CSDN博客_希尔排序是把记录按下标
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void ShellSort(vector& vec)
{
int n=vec.size();
if (n == 0)
return;
int gap = n;
while (gap > 1)
{
gap = gap / 2;
//Insert Sort
//from gap+1 on
for (int i = gap; i < n; ++i)
{
for (int j = i; j >=gap; j -= gap)
{
if (vec[j - gap] > vec[j])
{
int tmp = vec[j-gap];
vec[j - gap] = vec[j];
vec[j] = tmp;
}
}
}
}
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
ShellSort(vec);
PrintVec(vec);
return 0;
}
五、归并排序
十大经典排序算法-归并排序算法详解_小小学编程的博客-CSDN博客_归并排序算法
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void Merge(vector& vec, int l,int m, int r)
{
if (l >= r)
return;
int len = r - l + 1;
vector tmp(len);
int i = l, j = m + 1;
int k = 0;
while ((i <= m) && (j <= r))
{
if (vec[i] <= vec[j])
{
tmp[k++] = vec[i++];
}
else
{
tmp[k++] = vec[j++];
}
}
while (i <= m)
{
tmp[k++] = vec[i++];
}
while (j <= r)
{
tmp[k++] = vec[j++];
}
for (k = l; k <= r; k++)
{
vec[k] = tmp[k-l];
}
}
void MergeSort(vector& vec,int l,int r)
{
if (l >= r)
return;
int m = (l + r) / 2;
MergeSort(vec, l, m);
MergeSort(vec, m+1, r);
Merge(vec, l, m, r);
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
MergeSort(vec,0,vec.size()-1);
PrintVec(vec);
return 0;
}
六、快速排序
重点！！！必须牢牢掌握并且善于化用
注意：哨兵的选择和先移动左/右的关系
快速排序法（详解）_李小白~的博客-CSDN博客_快速排序
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void QuickSort(vector& vec, int l, int r)
{
if (l >= r)
{
return;
}
int i = l, j = r;
int pivot = vec[l];
while (i < j)
{
/*
此处非常重要！！！以最左边为pivot，则需要先移动右边j
*/
while (vec[j] >= pivot && i < j)
{
j--;
}
while (vec[i] <= pivot && i < j)
{
i++;
}
if (i < j)
swap(vec[i],vec[j]);
}
swap(vec[l],vec[i]);
QuickSort(vec,l,i - 1);
QuickSort(vec, i + 1, r);
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
QuickSort(vec, 0, vec.size() - 1);
PrintVec(vec);
return 0;
}
七、堆排序
https://blog.csdn.net/weixin_41545534/article/details/115567889?spm=1001.2014.3001.5506
堆排序算法（图解详细流程）_阿顾同学的博客-CSDN博客_堆排序的详细过程
#include
#include
using namespace std;
vector vec = {
3,5,8,7,9,4,14,15,82,37,27,45,66,1
};
void Adjust(vector& vec,int end, int idx)
{
int left_idx = 2 * idx + 1;
int right_idx = 2 * idx + 2;
int max_idx=idx;
if (left_idx < end && vec[left_idx]>vec[max_idx])
max_idx = left_idx;
if (right_idx < end && vec[right_idx]>vec[max_idx])
max_idx = right_idx;
//if changed
if (max_idx != idx)
{
swap(vec[max_idx],vec[idx]);
Adjust(vec,end, max_idx);
}
}
void HeapSort(vector& vec)
{
//Build Heap
int n = vec.size();
if (n == 0)
return;
for (int i = (n/2-1); i >=0; --i)
{
Adjust(vec, n,i);
}
//swap and re-adjust 0-i element
for (int i = n - 1; i >= 1; --i)
{
swap(vec[i],vec[0]);
Adjust(vec,i, 0);
}
}
void PrintVec(const vector& vec)
{
for (auto it : vec)
{
cout << it << " ";
}
cout << endl;
}
int main()
{
PrintVec(vec);
HeapSort(vec);
PrintVec(vec);
return 0;
}