Using a single-chain table with leading nodes in C language to simulate the stack structure

Using a single-chain table with leading nodes in C language to simulate the stack structure

In the previous two blogs, I used static arrays and dynamic arrays to construct stacks, which is convenient to implement. However, I always feel that flexibility is not enough, because no matter what, we must specify the length of the array. In this blog, we will use the single-chain table of the leading node to simulate the stack. Why is a single-chain table used? For stacks, pop-up and press-in operations are performed on the top of stacks. The operations on the first node in a single-chain table are the most convenient. The two match exactly. Upload the code to https://github.com/chenyufeng1991/stack_javaslist.

(1) Declare node types and functions

 

typedef int elemType;typedef struct NodeList{    int element;    struct NodeList *next;}Node;void createStack(Node **pNode);void destroyStack(Node *pNode);void push(Node *pNode,int value);void pop(Node *pNode);void top(Node *pNode);int isEmpty(Node *pNode);int isFull(Node *pNode);void printStack(Node *pNode);

(2) initialize a single-chain table

 

 

// Initialize the void createStack (Node ** pNode) {* pNode = (Node *) malloc (sizeof (Node); if (* pNode = NULL) {printf ("% s FUNCTION execution, memory allocation failed, single-chain table initialization failed \ n" ,__ FUNCTION _);} else {(* pNode)-> next = NULL; printf ("% s FUNCTION execution, leading node single-chain table initialization completed \ n" ,__ FUNCTION __);}}

(3) press an element

 

 

// Press a void push (Node * pNode, int value) {Node * pInsert; pInsert = (Node *) malloc (sizeof (Node )); // check whether the allocated memory is successfully pInsert = NULL? Memset (pInsert, 0, sizeof (Node); pInsert-> next = NULL; pInsert-> element = value; pInsert-> next = pNode-> next; pNode-> next = pInsert ;}

(4) An element is displayed.

 

 

// Pop up an element void pop (Node * pNode) {if (! IsEmpty (pNode) {Node * pNext; pNext = pNode-> next; pNode-> next = pNext-> next; free (pNext); pNext = NULL ;}}

(5) print stack Elements

 

 

// Print the stack element void printStack (Node * pNode) {if (! IsEmpty (pNode) {Node * pMove; pMove = pNode-> next; while (pMove! = NULL) {printf ("% d", pMove-> element); pMove = pMove-> next;} printf ("\ n ");} else {printf ("Stack is empty, print failed \ n ");}}

(6) Clear stack Elements

 

 

// Clear the stack element void destroyStack (Node * pNode) {Node * pMove; pMove = pNode-> next; while (pMove! = NULL) {pNode-> next = pMove-> next; free (pMove); pMove = pNode-> next ;}}

(7) judge whether the stack is empty

 

 

// Determine whether the stack is empty. int isEmpty (Node * pNode) {/*** when there is only one header Node, this linked list is blank */if (pNode-> next = NULL) {return 1;} return 0 ;}

(8) taking the top element of the stack

 

 

// Obtain the top element of the stack void top (Node * pNode) {if (! IsEmpty (pNode) {printf ("the top element of the stack is % d \ n", pNode-> next-> element );}}

(8) test code

 

 

Int main (int argc, const char * argv []) {Node * pList; createStack (& pList); push (pList, 3); push (pList, 1 ); push (pList, 9); push (pList, 4); push (pList, 7); printStack (pList); pop (pList ); printf ("the elements of the pop Stack are \ n"); printStack (pList); top (pList); destroyStack (pList); printStack (pList); return 0 ;}