lianzhan.cpp

关于数据结构的各章节的c原代码实现

// lianzhan.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
struct stack_node
{
int data;
struct stack_node *next;

};
typedef struct stack_node node;
typedef node *link;
link operater=NULL;
link oprand=NULL;
link push(link stack,int value)
{
	link newnode;
	newnode=(link)malloc(sizeof(node));
	if (!newnode)
	{
		printf("分配内存失败");
		return NULL;
	}
	newnode->data=value;
	newnode->next=stack;
	stack=newnode;
		return stack;
}
link pop(link stack,int *value)
{
	link temp;
	if(stack!=NULL)
	{
	temp=stack;
	stack=stack->next;
	*value=temp->data;
	free(temp);
	return stack;
	}
	else
		*value=-1;
}
int empty(link stack)
{
	if(stack==NULL)
		return 1;
	else
		return 0;
}
int isoperater(char op)
{
   switch (op)
   {
   case '+':
   case '-':
   case '*':
   case '/': return 1;
   default : return 0;
 
   }
}
int priority(char op)
{
    switch (op)
	{
	case '*':
	case '/': return 2;
	case '+':
	case '-': return 1;
	default : return 0;
		
	}

}
int getvalue(int op,int op1,int op2)
{
    switch ((char)op)
    {
	case '*': return (op2*op1);
    case '/': return (op2/op1);
	case '+': return (op2+op1);
	case '-': return (op2-op1);
    }
}
int main(int argc, char* argv[])
{   
	char exp[100];
	int result=0;
	int op1=0;
	int op2=0;
	int  op=0;
		int i=0;
	printf("输入表达式：");
	gets(exp);

	while (exp[i]!='\0'&&exp[i]!='\n')
	{
		if (isoperater(exp[i]))
		{
           while (!empty(operater)&&priority(exp[i])<=priority(operater->data))
           {
			   operater=pop(operater,&op);
			   oprand=pop(oprand,&op1);
			   oprand=pop(oprand,&op2);
			   oprand=push(oprand,getvalue(op,op1,op2));
           }
               operater=push(operater,exp[i]);
		}
		else
			oprand=push(oprand,exp[i]-48);
		i++;
	}
while (!empty(operater))
{
    operater=pop(operater,&op);
	oprand=pop(oprand,&op1);
	oprand=pop(oprand,&op2);
	oprand=push(oprand,getvalue(op,op1,op2));
}
    oprand=pop(oprand,&result);
	printf("表达式的结果是%d\n",result);
	return 0;
}