c/c++语言开发共享C语言用栈模拟实现队列问题详解

ypedef char stdatatype;    typedef struct stack  {  	stdatatype* a;  	int top;  	int capacity;  }st;    //初始化结构体  void stackinit(st* ps);  //销毁结构体  void stackdestroy(st* ps);  //压栈  void stackpush(st* ps, stdatatype x);  //出栈  void stackpop(st* ps);  //得到栈顶的值  stdatatype stacktop(st* ps);  //判断栈是否为空  bool stackempty(st* ps);  //得到栈的长度  int stacksize(st* ps);      //初始化结构体  void stackinit(st* ps)  {  	assert(ps);  	ps->a = null;  	ps->capacity = 0;  	ps->top = 0;  }  //销毁结构体  void stackdestroy(st* ps)  {  	assert(ps);  	free(ps->a);  	ps->a = null;  	ps->capacity = 0;  	ps->top = 0;      }  //压栈  void stackpush(st* ps, stdatatype x)  {    	assert(ps);  	if (ps->top == ps->capacity)  	{  		int newcapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;  		stdatatype* new = (stdatatype*)realloc(ps->a, sizeof(stdatatype) * newcapacity);  		if (new == null)  		{  			printf("realloc failn");  			exit(-1);  		}  		ps->a = new;  		ps->capacity = newcapacity;  	}  	ps->a[ps->top] = x;  	ps->top++;  }  void stackpop(st* ps)  {  	assert(ps);  	assert(ps->top > 0);  	ps->top--;  }  stdatatype stacktop(st* ps)  {  	assert(ps);      assert(ps->top>0);  	return ps->a[ps->top-1];  }  bool stackempty(st* ps)  {  	assert(ps);  	return ps->top == 0;  }  //得到栈的长度  int stacksize(st* ps)  {  	assert(ps);  	return ps->top;  }        //创建了两个栈  typedef struct   {      st st1;      st st2;    } myqueue;    //对两个栈进行初始化。  myqueue* myqueuecreate()   {      myqueue* newqueue = (myqueue*)malloc(sizeof(myqueue));      assert(newqueue);      stackinit(&newqueue->st1);      stackinit(&newqueue->st2);        return newqueue;    }    void myqueuepush(myqueue* obj, int x)   {      assert(obj);      stackpush(&obj->st2, x);    }    int myqueuepop(myqueue* obj)   {       assert(obj);       if(stackempty(&obj->st1))       {          while(!stackempty(&obj->st2))          {            stackpush(&obj->st1,  stacktop(&obj->st2));              stackpop(&obj->st2);          }       }          int top = 0;       if(!stackempty(&obj->st1))       {           top = stacktop(&obj->st1);           stackpop(&obj->st1);       }          return top;  }    int myqueuepeek(myqueue* obj)   {     assert(obj);       if(stackempty(&obj->st1))       {          while(!stackempty(&obj->st2))          {            stackpush(&obj->st1,  stacktop(&obj->st2));              stackpop(&obj->st2);          }       }          if(!stackempty(&obj->st1))       {           return stacktop(&obj->st1);       }       return 0;  }    bool myqueueempty(myqueue* obj)  {      return stackempty(&obj->st1) && stackempty(&obj->st2);  }    void myqueuefree(myqueue* obj)   {      stackdestroy(&obj->st1);      stackdestroy(&obj->st2);      free(obj);  }