Quick sort: O(n2)
True correct Quick sort:
#include
#include
using namespace std;
int a[100];
/*void swap(int a,int b){
int tmp;
tmp=a;
a=b;
b=tmp;
}*/
void quicksort(int left,int right){
int i,j,t;
if(left>right)
return;
int temp=a[left];
i=left;
j=right;
while(i<j){
while(a[j]>temp&&i<j)
j--;
a[i]=a[j];
while(a[i]j)
i++;
a[j]=a[i];
}
a[i]=temp;
quicksort(left,i-1);
quicksort(i+1,right);
}
int main(){
int num;
cin>>num;
for(int i=1;i<=num;i++)
scanf_s("%d",&a[i]);
quicksort(1,num);
for(int i=1;i<=num;i++)
cout<endl;
return 0;
}
Insert sort: O(n2)
#include
#include
using namespace std;
int a[100];
int main(){
int n;
cin>>n;
for(int i=0;icin>>a[i];
for(int i=1;iif(a[i] int j=i-1;
int x=a[i];
while(j>=0&&a[j]>x){
a[j+1]=a[j];//It is found that the former number is greater than the latter number
Move the following number back.
j--;
}
a[j+1]=x;//Insert the number to be compared
}
}
for(int i=0;icout< return 0;
}
Merge and sort: O(nlogn)
#include
#include
using namespace std;
void merge(vector<int> &arr,< span style="color: #0000ff;">int L,int mid,int R){
int *help = new int(R-L+1);
int p1=L,p2=mid+1, i=0;
while(p1<=mid && p2<=R) {
help[i++] = arr[p1]>arr[p2]? arr[p2++]: arr[p1++];
}
while(p1<=mid)
help[i++] = arr[p1++];
while(p2<=R)
help[i++] = arr[p2++];
for (int i=0;i1;i++)
{
arr[L+i] = help[i];
}
}
void sortprocess(vector<int> &arr,< span style="color: #0000ff;">int L,int R)
{ if (L < R) {
int mid = L + ((RL)>>2 span>); // (L+R)/2
sortprocess(arr,L,mid);
sortprocess(arr,mid+1,R);
merge(arr,L,mid,R); }}
void MergeSort(vector<int> &arr,< span style="color: #0000ff;">int L,int R){
if (arr.size()<2< span style="color: #000000;">)
return; sortprocess(arr,L,R);}
int main(){
vector<int> arr;
int n,temp; cin>>n; // span>Enter n number
for (int i=0;i) >>temp; //Enter data
{
cin
arr.push_back(temp);
}
MergeSort(arr,0,arr.size()-1< /span>);
for(int i=0;i) <
coutendl;
system("pause");
return 0;
}
Really correct quick sort:
#include
#include
using namespace std;
int a[100];
/*void swap(int a,int b){
int tmp;
tmp=a;
a=b;
b=tmp;
}*/
void quicksort(int left,int right){
int i,j,t;
if(left>right)
return;
int temp=a[left];
i=left;
j=right;
while(i<j){
while(a[j]>temp&&i<j)
j--;
a[i]=a[j];
while(a[i]j)
i++;
a[j]=a[i];
}
a[i]=temp;
quicksort(left,i-1);
quicksort(i+1,right);
}
int main(){
int num;
cin>>num;
for(int i=1;i<=num;i++)
scanf_s("%d",&a[i]);
quicksort(1,num);
for(int i=1;i<=num;i++)
cout<endl;
return 0;
}
#include
#include
using namespace std;
int a[100];
int main(){
int n;
cin>>n;
for(int i=0;icin>>a[i];
for(int i=1;iif(a[i] int j=i-1;
int x=a[i];
while(j>=0&&a[j]>x){
a[j+1]=a[j];//It is found that the former number is greater than the latter number
Move the following number back.
j--;
}
a[j+1]=x;//Insert the number to be compared
}
}
for(int i=0;icout< return 0;
}
#include
#include
using namespace std;
void merge(vector<int> &arr,< span style="color: #0000ff;">int L,int mid,int R){
int *help = new int(R-L+1);
int p1=L,p2=mid+1, i=0;
while(p1<=mid && p2<=R) {
help[i++] = arr[p1]>arr[p2]? arr[p2++]: arr[p1++];
}
while(p1<=mid)
help[i++] = arr[p1++];
while(p2<=R)
help[i++] = arr[p2++];
for (int i=0;i1;i++)
{
arr[L+i] = help[i];
}
}
void sortprocess(vector<int> &arr,< span style="color: #0000ff;">int L,int R)
{ if (L < R) {
int mid = L + ((RL)>>2 span>); // (L+R)/2
sortprocess(arr,L,mid);
sortprocess(arr,mid+1,R);
merge(arr,L,mid,R); }}
void MergeSort(vector<int> &arr,< span style="color: #0000ff;">int L,int R){
if (arr.size()<2< span style="color: #000000;">)
return; sortprocess(arr,L,R);}
int main(){
vector<int> arr;
int n,temp; cin>>n; // span>Enter n number
for (int i=0;i) >>temp; //Enter data
{
cin
arr.push_back(temp);
}
MergeSort(arr,0,arr.size()-1< /span>);
for(int i=0;i) <
coutendl;
system("pause");
return 0;
}