#include<stdio.h>#include<stdlib.h>#include<malloc.h>//定義結點結構體typedef struct Node{ int data;  //內容 struct Node * pNext; //指向下一結點的指針} NODE, * PNODE;  //NODE等價于struct Node, PNODE等價于struct Node *//定義棧的結構體typedef struct Stack{ PNODE pTop;  //棧頂結點 PNODE pBottom;  //棧底結點} STACK, * PSTACK;  //STACK等價于struct Stack, PSTACK等價于struct Stack *//函數聲明void initStack(PSTACK pStack);  //對棧進行初始化的函數void pushStack(PSTACK pStack, int val); //入棧的函數bool popStack(PSTACK pStack, int * pVal);//出棧的函數，*pVal用來保存出棧的元素內容void traverseStack(PSTACK pStack);  //遍歷棧的函數bool isEmpty(PSTACK pStack);  //判斷棧是否為空的函數void clearStack(PSTACK pStack);  //清空棧的函數int main(void){ STACK stack;  //定義一個棧變量,STACK等價于struct Stack int val;  //用來保存出棧的內容 initStack(&stack); //調用棧的初始化函數 pushStack(&stack, 10); //調用入棧的函數 pushStack(&stack, 20); pushStack(&stack, 30); pushStack(&stack, 50); traverseStack(&stack); //調用遍歷棧的函數 //調用出棧的函數 if(popStack(&stack, &val)) printf("出棧成功，出棧的元素值為：%d/n", val); else printf(" 出棧失敗!"); //調用清空棧的函數 clearStack(&stack); traverseStack(&stack); //調用遍歷棧的函數 system("pause"); return 0;}void initStack(PSTACK pStack){ //創建一個空結點，讓pTop指向它 pStack->pTop = (PNODE)malloc(sizeof(NODE)); if(NULL != pStack->pTop) { //將pBottom也指向空節點 pStack->pBottom = pStack->pTop; //清空空結點的指針域 pStack->pTop->pNext = NULL; } else   //如果內存分配失敗 { printf("內存分配失敗!程序退出!/n"); exit(-1); } return;}void pushStack(PSTACK pStack, int val){ //動態創建一個新結點 PNODE pNew = (PNODE)malloc(sizeof(NODE)); //設置新結點的數據域的值 pNew->data = val; //將新結點的指針域指向之前建的空節點 pNew->pNext = pStack->pTop;  //pStack->pTop不能換成pStack->pBottom //pTop指向新的結點 pStack->pTop = pNew; return;}bool popStack(PSTACK pStack, int * pVal){ if(isEmpty(pStack)) { return false; } else { //先保存棧頂元素的地址，然后將pTop指向下一元素,最后釋放之前棧頂元素的內存 PNODE rNode = pStack->pTop; *pVal = rNode->data; pStack->pTop = rNode->pNext; free(rNode); rNode = NULL; return true; }}void traverseStack(PSTACK pStack){ //將棧頂賦給一個臨時結點,因為在遍歷棧的時候不能銷毀棧 PNODE pNode = pStack->pTop; //循環遍歷棧,直到棧底 while(pStack->pBottom != pNode ) { printf("%d ", pNode->data); pNode = pNode->pNext; } printf("/n"); return;}bool isEmpty(PSTACK pStack){ if(pStack->pTop == pStack->pBottom) return true; else return false;}void clearStack(PSTACK pStack){ //棧為空，則退出該函數 if(isEmpty(pStack)) { return; } else {  //兩個結點指針變量用來釋放棧中元素的內存 PNODE p = pStack->pTop; PNODE q = NULL; //循環釋放內存 while(p != pStack->pBottom) {  q = p->pNext;  free(p);  p = q; } //將棧頂和棧底指向同一個指針域為空的結點 pStack->pTop = pStack->pBottom; return; }}