Simple sort implementation of C-way linked list

Today, I occasionally see a single necklace list of C structures.

So re-review the next two-way list, rewrite the next two-way list of simple sorting implementation, as a review summary.

Define a doubly linked list first

1 struct student{2     int StudentID; 3     Char * name; 4     Student *next, * last; 5 };

Then there is the key sorting method:

intSortbyname (Student *p) {Student*head =p; //start sorting from the head of the list (you can also get rid of the words that are sorted from the incoming node)     while(Head->last! =NULL) {Head= head->Last ; }     while(Head! =NULL) {Student*headnext = head->Next;  while(Headnext! =NULL) {            if(strcmp (Head->name, Headnext->name) >0) {swapstudent (head, Headnext); //Note that this must be exchanged because the location of the linked list node is changedStudent *tmp =Head; Head=Headnext; Headnext=tmp; } Headnext= headnext->Next; } head= head->Next; }    return 1;}

It also involves a swapstudent method, which realizes the function of exchanging two nodes.

The code is as follows:

voidSwapstudent (Student *s1, Student *S2) {    if(S1->next = =S2) {        if(S2->next! =NULL) {S2->next->last =S1; }        if(S1->last! =NULL) {S1->last->next =S2; } S1->next = s2->Next; S2->last = s1->Last ; S1->last =S2; S2->next =S1; }Else if(S1->last = =S2) {        if(S1->next! =NULL) {S1->next->last =S2; }        if(S2->last! =NULL) {S2->last->next =S1; } S2->next = s1->Next; S1->last = s2->Last ; S2->last =S1; S1->next =S2; }Else{        //It's important to note that the value of the upper and lower nodes in the node adjacent node is updated//I've been in this hole for a long time to find out.//The above two cycle bodies also need to be aware of        if(S1->next! =NULL) {S1->next->last =S2; }        if(S1->last! =NULL) {S1->last->next =S2; }        if(S2->next! =NULL) {S2->next->last =S1; }        if(S2->last! =NULL) {S2->last->next =S1; } Student*s1next = s1->Next; Student*s1last = s1->Last ; S1->next = s2->Next; S1->last = s2->Last ; S2->next =S1next; S2->last =S1last; }}

Above is the core implementation of the simple sort implementation.

If you look carefully, you will notice a problem.

If you use bubble sort, the swap method above can be implemented simply because only the adjacent two nodes are exchanged.

I write this to be more generalized, the node operation requirements are higher, to facilitate their understanding.

Simple sort implementation of C-way linked list