Basic operations of a linked list-two-way linked list

The two-way linked list is also determined by the unique header pointer.
A two-way linked list can be connected at the beginning and end of a chain table.

/* Basic operations on the linked list ~~ Development Environment: vs2010win32 console application. */# include "stdafx. H "# include <iostream> using namespace STD; struct node {int data; node * Next; // points to the node * pre; // points to the frontend node }; node * createbidirlist (int n); void outputbidirlist (node * head); node * insertdata (int n, node * head); node * deletedata (int n, node * head ); int main () {int N; node * listhead = NULL; cout <"Please enter the number of nodes:"; CIN> N; // you can enter 5 (1 2 3 4 5) if (n> 0) listhead = createbidirlist (n); outputbidirlist (listhead); insertdata (7, listhead ); outputbidirlist (listhead); insertdata (6, listhead); deletedata (2, listhead); outputbidirlist (listhead); Return 0 ;}

// Create a two-way linked list node * createbidirlist (int n) {node * temp, * tail = NULL, * head = NULL; int num; CIN> num in the order of data input; head = new node; // dynamically allocates memory for the new node if (Head = NULL) {cout <"no memory available! "; Return NULL;} else {head-> DATA = num; head-> next = NULL; head-> pre = NULL; tail = head ;} for (INT I = 0; I <n-1; I ++) {CIN> num; temp = new node; // dynamically allocate memory for the new node if (temp = NULL) {cout <"no memory availabe"; return head;} else {temp-> DATA = num; temp-> next = NULL; temp-> pre = tail; tail-> next = temp; tail = temp;} return head ;}

 

 

// Output the value of the data member of each node in the two-way linked list void outputbidirlist (node * head) {cout <"list:"; node * curnode = head; while (curnode) {If (curnode-> pre) cout <"<-"; cout <curnode-> data; If (curnode-> next) cout <"-> "; curnode = curnode-> next;} cout <Endl; return ;}

// Insert the integer n into a sorted two-way linked list (from small to large) node * insertdata (int n, node * head) {node * curnode = head; // point to the node after the insertion point * prenode = NULL; // point to the node before the insertion point * newnode = NULL; // point to the new node // find the insert position while (curnode! = NULL) & (curnode-> data <n) {prenode = curnode; curnode = curnode-> next;} newnode = new node; // dynamically allocate memory for the new node if (newnode = NULL) {// memory allocation failure cout <"not memory available! "; Return head;} newnode-> DATA = N; If (prenode = NULL) {// newnode-> next = curnode; newnode-> pre = NULL; if (curnode! = NULL) curnode-> pre = newnode; return newnode;} If (curnode = NULL) {// newnode-> pre = prenode; prenode-> next = newnode; newnode-> next = NULL; return head;} else {// prenode-> next = newnode; newnode-> next = curnode; newnode-> pre = prenode; curnode-> pre = newnode; return head ;}}

// Search for and delete the specified node * deletedata (int n, node * head) {node * curnode = head in the two-way linked list; // point to the current node while (curnode & curnode-> data! = N) curnode = curnode-> next; If (curnode = NULL) {cout <"can't find" <n <Endl; return head ;} if (curnode-> pre = NULL) {head = head-> next; head-> pre = NULL ;} else {curnode-> pre-> next = curnode-> next; If (curnode-> next! = NULL) curnode-> next-> pre = curnode-> pre;} Delete curnode; return head; // return the first pointer of the chain}