//堆栈–>后进先出，先进后出
#include<stdio.h>
#include<stdlib.h>
struct stackNode{
int data;
struct stackNode *nextPtr;
};
typedef struct stackNode Stacknode;
typedef Stacknode* StacknodePtr;
void push(StacknodePtr *topPtr, int number);
int pop(StacknodePtr *topPtr);
void printList(StacknodePtr topPtr);
int isEmpty(StacknodePtr topPtr);
int main()
{
StacknodePtr startPtr = NULL;
int choice;
int value;
printf("Enter your choice from the following.\n"" 1 to fill the number at the list top.\n"" 2 to remove the number from the list top.\n"" 3 to end.\n? ");scanf("%d", &choice);while(choice != 3){switch(choice){case 1:printf("Enter an integer: \n");scanf("%d", &value);push(&startPtr, value);printf("%d has been added into the list.\n"" The list after adding a value is\n", value);printList(startPtr);break;case 2:if(!isEmpty(startPtr)){printf("%d has been deleted from the list.\n", pop(&startPtr));printf("The list after deleted is :\n");printList(startPtr);}else{printf("The list is empty.\n");printf("Please choose a command again.\n");}break;default:printf("You enter a wrong command,\n");printf("Please choose a command again.\n");break;}printf("? ");scanf("%d", &choice);}printf("End of run.\n");return 0;
}
void push(StacknodePtr *topPtr, int number)
{
StacknodePtr newPtr; //用于存放要放入的结构（节点）
newPtr = (StacknodePtr)malloc(sizeof(Stacknode));if(newPtr == NULL){printf("No memmery is available.\n");} else{newPtr->data = number;newPtr->nextPtr = *topPtr;*topPtr = newPtr;}
}
int pop(StacknodePtr *topPtr)
{
int backnumber;
StacknodePtr tempPtr;
tempPtr = *topPtr;backnumber = tempPtr->data;*topPtr = (*topPtr)->nextPtr;free(tempPtr);return backnumber;
}
void printList(StacknodePtr topPtr)
{
if(topPtr == NULL){
printf(“NULL\n”);
}
else{
while(topPtr != NULL){
printf("%d–>", topPtr->data);
topPtr = topPtr->nextPtr;
}
printf(“NULL\n”);
}
}
int isEmpty(StacknodePtr topPtr)
{
if(topPtr == NULL){
return 1;
}
else{
return 0;
}
}
