Lisa
这个傲娇的计算器叫Lisa。
/*********************************************************
Code writer : EOF
Code file : stack.h
Code date : 2014.11.26
Email : jasonleaster@gmail.com
Code description:
Here is a implementation of a naive computer
It based on two stack scheme which was found by Dijkstra.
*********************************************************/
#ifndef _STACK_H
#define _STACK_H 1
#define EMPTY 0
#define NON_EMPTY 1
#define ARRAYSIZE 1024
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
struct node
{
int data;
struct node* next;
};
int computer(void);
struct node* creat_stack(void);
int push_stack(struct node** pp_top,int number);
int is_empty(struct node* p_node);
void release_stack(struct node* p_top);
#endif
/*************************************************************
code writer : EOF
Code file : computer_test.c
code date : 2014.03.03
e-mail : jasonleaster@gmail.com
code purpose :
This is just a test code for "Lisa" that
I created. If there is something wrong with my code, please
touche me by e-mail.
#ATTENTION#
You must input with '(' and ')' for each operator,
otherwise you will be puzzle about the result of output.
Usage:
(1+2) would output 3
(1+((2*3)+1)) == 8
If there is something wrong with my code, please touch me by e-mail.
******************************************************************/
#include "stack.h"
int main()
{
int number = 0;
printf("Hello ! This is a naive computer."
"Her name is 'Lisa' :)\n");
number = computer();
printf("The result of your inputed :%d\n",number);
return 0;
}
/*********************************************************
Code writer : EOF
Code file : computer.c
Code date : 2014.11.26
Email : jasonleaster@gmail.com
Version : 0.0
Code description:
code purpose :
This code is my implementation for function creat_stack.
functin creat_stack would creat a the first node of the stack and
just only the first node. You must know what is stack...
#ATTENTION#
You must input with '(' and ')' for each operator,
otherwise you will be puzzle about the result of output.
Usage:
(1+2) would output 3
(1+((2*3)+1)) == 8
If there is something wrong with my code, please touch me by e-mail.
*********************************************************/
#include "stack.h"
int computer(void)
{
char string[ARRAYSIZE] = {0};
/*
** According to Dijsktra's Two Stack scheme,
** we creat two stack.
** @p_stack_operand is pointer which point to
** a stack only for operand in the inputed string.
** So do @p_stack_operator.
*/
struct node* p_stack_operand = NULL;
struct node* p_stack_operator = NULL;
p_stack_operand = creat_stack();
p_stack_operator = creat_stack();
int temp = 0;
int result = 0;
int opr_one = 0;
int opr_two = 0;
char operator = 0;
/*
** Evil --> --> scanf("%s",&string);
**
** scanf family is not safe for string which is inputed.
** I decide to give it up and use system call read().
*/
if(read(STDIN_FILENO,string,ARRAYSIZE) < 0)
{
printf("system call read() error"
" in function %s()\n",__FUNCTION__);
}
for(temp = 0;string[temp] != '\n';temp++)
{
if(string[temp] == '(')
{
continue;
}
if(string[temp] == ')')
{
opr_one = pop_stack(p_stack_operand);
opr_two = pop_stack(p_stack_operand);
operator = pop_stack(p_stack_operator);
switch(operator)
{
case '+':
{
push_stack(&p_stack_operand,
opr_one + opr_two);
break;
};
case '-':
{
push_stack(&p_stack_operand,
opr_one - opr_two);
break;
};
case '*':
{
push_stack(&p_stack_operand,
opr_one * opr_two);
break;
};
case '/':
{
push_stack(&p_stack_operand,
opr_one / opr_two);
break;
};
default:
goto out;
result = -1;
printf("ERROR!undefined "
"operator %c\n",operator);
}
}
if(string[temp] >= '0' && string[temp] <= '9')
{
push_stack(&p_stack_operand,string[temp] - '0');
continue;
}
if(string[temp] == '+' || string[temp] == '-'||
string[temp] == '*' || string[temp] == '/')
{
push_stack(&p_stack_operator,string[temp]);
continue;
}
}
/*
** Finally, We got the result which is stored in stack--operand
*/
result = pop_stack(p_stack_operand);
out:
release_stack(p_stack_operand);
release_stack(p_stack_operator);
return result;
}
/*********************************************************************
code writer : EOF
code date : 2014.03.03
e-mail : jasonleaster@gmail.com
**********************************************************************/
#include "stack.h"
struct node* creat_stack(void)
{
struct node* p_top = NULL;
p_top = (struct node*)malloc(sizeof(struct node));
if(p_top == NULL)
{
printf("malloc failed\n");
}
p_top->next = NULL;
while(is_empty(p_top) == NON_EMPTY)
{
pop_stack(p_top);
}
return p_top;
}
/**********************************************************************
code writer: EOF
code date : 2014.03.03
e-mail: jasonleaster@gmail.com
code purpose :
This code is a implementation for function is_empty
If there is something wrong with my code, please touch me by e-mail.
**********************************************************************/
#include "stack.h"
int is_empty(struct node* p_node)
{
if(p_node->next == NULL)
{
return EMPTY;
}
else
{
return NON_EMPTY;
}
}
/*****************************************************************
code writer: EOF
code date: 2014.03.03
e-mail: jasonleaster@gmail.com
code purpose :
This code is a implementation for function pop_stack
If there is something wrong with my code, please touch me by e-mail
*****************************************************************/
#include "stack.h"
int pop_stack(struct node* p_top)
{
struct node* temp = NULL;
int number = 0;
if(is_empty(p_top) == EMPTY)
{
printf("empty stack!\nprocess end");
return EMPTY;
}
else
{
temp = p_top->next;
p_top->next = p_top->next->next;
number = temp->data;
free(temp);
}
return number;
}
/*******************************************************************
code writer : EOF
code date:2014.03.03
e-mail:jasonleaster@gmail.com
code purpose :
This is my implementaion for function push_stack
If there is somrthing wrong with my code, please touche me by e-mail.
*******************************************************************/
#include "stack.h"
int push_stack(struct node** pp_top,int number)
{
struct node* temp = NULL;
struct node* new_node = NULL;
new_node = (struct node*)malloc(sizeof(struct node));
if(new_node == NULL)
{
printf("malloc failed\nprocess end\n");
return 0;
}
new_node->data = number;
new_node->next = (*pp_top)->next;
(*pp_top)->next = new_node;
}
#include "stack.h"
void release_stack(struct node* p_top)
{
while(is_empty(p_top) == NON_EMPTY)
{
pop_stack(p_top);
}
}测试时，要严格按照输入要求进行测试！
欢迎提出发现的bug，或者指正编码风格不好的地方。
原文地址：http://blog.csdn.net/cinmyheart/article/details/41518775
