[数据结构]链栈的创建，入栈和出栈

栈是一种在栈顶压入和弹出的数据结构，所以只在一端进行操作.为了减小遍历开支，所以链栈一般在首元节点处进行插入（入栈）.

#include <stdio.h>
#include <stdlib.h>typedef struct Node {int data;struct Node* next;}Node;
Node* pushStack(Node* , int); 
void print_Stack(Node* );
Node* popStack(Node* ptr,int* popvalue);
int main() 
{Node* ptr = NULL; int value = 0,popvalue=0;/*数据进行入栈*/for (int i = 0; i < 10; i++) {value = 10 * i + 10;ptr=pushStack(ptr, value);}print_Stack(ptr);    ptr=popStack(ptr,&popvalue);printf("popvalue=%d\n",popvalue);print_Stack(ptr);return 0;
}
/*执行压栈操作*/
Node* pushStack(Node* ptr, int pushvalue) 
{if (ptr == NULL){Node* newNode = (Node*)malloc(sizeof(Node));ptr = newNode; newNode->next = NULL; newNode->data = pushvalue;}else {Node* newNode = (Node*)malloc(sizeof(Node));newNode->data = pushvalue;newNode->next = ptr;ptr = newNode;}return ptr;
}void print_Stack(Node* ptr)
{Node* str=ptr;while (str->next!=NULL) {printf("%d\n", str->data);str = str->next;}printf("%d\n", str->data);
}
/*执行出栈操作*/
Node* popStack(Node* ptr,int* popvalue)
{    Node* delete_ptr=NULL;*popvalue=ptr->data;delete_ptr=ptr;ptr=ptr->next;free(delete_ptr);delete_ptr=NULL;    return ptr;
}

 出栈返回栈顶数据代码：

#include <stdio.h>
#include <stdlib.h>typedef struct Node {int data;struct Node* next;
}Node;
Node* pushStack(Node* , int); void print_Stack(Node* );
int popStack(Node** ptr,int popvalue);int main() 
{Node* ptr = NULL; int value = 0,popvalue=0;/*数据进行入栈*/for (int i = 0; i < 10; i++) {value = 10 * i + 10;ptr=pushStack(ptr, value);}print_Stack(ptr);    popvalue=popStack(&ptr,popvalue);printf("popvalue=%d\n",popvalue);print_Stack(ptr);return 0;
}/*执行压栈操作*/
Node* pushStack(Node* ptr, int pushvalue) 
{if (ptr == NULL){Node* newNode = (Node*)malloc(sizeof(Node));ptr = newNode; newNode->next = NULL;newNode->data = pushvalue;}else {Node* newNode = (Node*)malloc(sizeof(Node));newNode->data = pushvalue;newNode->next = ptr;ptr = newNode;}
return ptr;
}void print_Stack(Node* ptr)
{Node* str=ptr;while (str->next!=NULL) {printf("%d\n", str->data);str = str->next;}printf("%d\n", str->data);
}/*进行出栈操作*/
int popStack(Node** ptr,int popvalue)
{   Node* delete_ptr=NULL;popvalue=(*ptr)->data;delete_ptr=*ptr;*ptr=((*ptr)->next);free(delete_ptr);delete_ptr=NULL;    return popvalue;
}

修改为具有头指针的形式