数据结构——链栈的基本操作

#include <iostream>using namespace std;typedef struct stacknode{    int data;    struct stacknode * next;}StackNode,* LinkStack;//判栈空int StackEmpty(LinkStack top){      if(top->next==NULL)          return 1;      else          return 0;}//入栈函数LinkStack Push(LinkStack top,int value){    StackNode * newp = (StackNode *)malloc(sizeof(StackNode));    if(newp != NULL)    {        newp->data=value;        newp->next=top->next;        top->next=newp;    }    else        cout<<"No memory available"<<endl;    return top;}//出栈函数int Pop(LinkStack top){    StackNode * temp;    int t;    if(StackEmpty(top))        cout<<"the stack is empty"<<endl;    else    {        temp=top->next;        t=temp->data;        top->next = temp->next;        free(temp);    }    return t;}//打印函数void PrintStack(LinkStack top){    if(top->next==NULL)        cout<<"the stack is empty"<<endl;    else    {        while(top->next!=NULL)        {            cout<<top->next->data<<"  ";            top=top->next;        }    }}//取栈顶元素int StackTop(LinkStack top){      if(StackEmpty(top))           cout<<"the Stack is empty"<<endl;      return top->next->data;}//栈的长度int StackLen(LinkStack top){    int len=0;        while(top->next!=NULL)        {            len++;            top=top->next;        }    return len;}//销毁栈void DestroyStack(LinkStack top){     LinkStack q;     while(top)     {          q=top->next;          delete top;          top=q;     }     printf("销毁成功");}//栈初始化void InitStack(LinkStack top){      top->next=NULL; }//前导函数void instruction(void){    cout<<"0------退出程序"<<endl        <<"1------入栈操作"<<endl        <<"2------出栈操作"<<endl        <<"3------取栈顶元素"<<endl        <<"4------判断栈是否为空"<<endl        <<"5------返回栈的元素个数"<<endl        <<"6------####初始化栈###"<<endl        <<"7------显示栈"<<endl        <<"8------销毁栈"<<endl        <<"9------退出程序"<<endl;}int main(){    LinkStack top;    top = (LinkStack)malloc(sizeof(StackNode));    //注意        instruction();    int i,value;        cin>>i;    while(i)    //输入0也可以退出循环    {        switch(i)        {                        case 1:        //入栈操作                InitStack(top);                cout<<"Input an integer"<<endl;                cin>>value;                while(value!=0)                {                    Push(top,value);    //入栈                    cin>>value;                }                PrintStack(top);    //打印栈                cout<<endl;                break;            case 2:        //出栈操作                if(top->next!=NULL)                    cout<<"the popped value is:"<<Pop(top)<<endl;    //出栈                else                    cout<<"the stack is empty"<<endl;                break;            case 3:        //取栈顶元素                if(StackEmpty(top)==1)                    cout<<"is empty"<<endl;                else                    cout<<StackTop(top)<<endl;                break;            case 4:        //判断栈是否为空                if(StackEmpty(top)==1)                    cout<<"is empty"<<endl;                else                    cout<<"is not empty"<<endl;                break;            case 5:        //返回栈的元素个数                if(StackEmpty(top)==1)                    cout<<"is empty"<<endl;                cout<<StackLen(top)<<endl;                cout<<endl;                break;            case 6:        //初始化栈                InitStack(top);break;            case 7:        //显示栈                PrintStack(top);                cout<<endl;break;            case 8:        //销毁栈                DestroyStack(top);                cout<<endl;break;            case 9:                goto end;            default:                cout<<"Invalid choice"<<endl;break;        }        instruction();            cin>>i;    }    end:;    //利用goto语句退出循环    return 0;}//简短的出栈入栈函数，数组实现/*    #include <stdio.h>    int stack[100]; //100个栈空间    int* sp = stack; //栈指针指向栈底    #define push( i ) { *sp++ = i; } //push一个数    #define pop() (*--sp) //pop一个数并返回    int main()    {        int i;        for ( i = 0; i < 10; ++i )//push 0~9        push( i );        for ( i = 0; i < 10; ++i )//输出9~0        printf( "%d ", pop() ) ;    }*/