#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define maxl 128
int pointer=0;
char judgement='y';
int shuzi(char ab[],int is); /*判断字符串ab中的字符是否都是合法字符*/
/*合法返回0，否则返回1*/
double change(char s[],int *st);
int kuohao(char s[],int is);/*判断字符串s中的左右括号个数是否匹配*/
/*匹配返回0，不匹配返回1*/
void inim(int ck[]);/*初始化合法字符列表ck*/
void calit(double s1[],int *to1,char s2[],int *to2,char tem);
void nospace(char s[]);/*去除字符串s中的空格*/
int importance[maxl];
main(){
double ans=0.0;
char pin[maxl],temp,stack2[maxl];/*stack2 为符号栈*/
int i,top1,top2,lenth;
double stack1[maxl];/*操作数栈*/
for (i=0;i<=maxl;++i) importance[i]=0;
printf("\n***********************************\n");
printf("* Welcome to use my calculator!!!!*\n");
printf("* *\n");
printf("* You can input a representation *\n");
printf("* then the machine will get the *\n");
printf("* result. *\n");
printf("* If you want to use the result *\n");
printf("* last time ,you can use a 'a' or *\n");
printf("* a 'A',at the first time they are*\n");
printf("* zero,be careful. *\n");
printf("***********************************\n");
inim(importance);
while((judgement=='y')||judgement=='Y')
{
printf("\n\nPlease input a representation\n");
while(1)
{
pointer=0;i=0;top1=-1;top2=0;lenth=0;/*显式初始化*/
stack2[0]='#';
gets(pin);/*pin中存放的是输入的表达式*/
nospace(pin);/*先对pin中的表达式去除空格*/
lenth=strlen(pin)-1;
if (shuzi(pin,lenth))/*shuzi(pin)判断pin中的表达式是否合法*/
{
printf("\nNot a right input,you must input again.\n");
continue;
}
if (kuohao(pin,lenth))/*kuohao(pin)判断pin中的表达式中的括号是否能匹配*/
{
printf("\nyou may lost a'(' or a ')',please input again\n");
continue;
}
if (pin[0]==45)
{
if (pin[1]=='(')
{
stack2[++top2]='-';
stack1[++top1]=0;
i=1;
}
else
{
++i;
stack1[++top1]=0-change(pin,&i);
++i;
}
}
while(i<=lenth)
{
temp=pin[i];
if(((temp<='9')&&(temp>='0'))||(temp=='.')||((temp=='-')&&(importance[pin[i-1]]!=(-3))))
{
stack1[++top1]=change(pin,&i);
}
else
{
if ((temp=='a')||(temp=='A'))
{
stack1[++top1]=ans;
}
else
{
if (importance[temp]>=importance[stack2[top2]])/*判断运算符的优先级*/
/*如果当前操作的优先级高于之前操作的优先级，压栈*/
{
stack2[++top2]=temp;
}
else
{
calit(stack1,&top1,stack2,&top2,temp);
if (pointer) continue;
stack2[++top2]=temp;
if(temp==')') top2-=2;
}
}
}
++i;
}
calit(stack1,&top1,stack2,&top2,'#');
if (pointer) continue;
printf("the result is \n");
printf("%lf\n",ans=stack1[0]);
break;
}
printf("\ncontinue(y/n)?");
judgement=getch();
while((judgement!='y')&&(judgement!='Y')
&&(judgement!='n')&&(judgement!='N'))
{
printf("\nyou need to input again.\n");
judgement=getch();
}
}
printf("\n***********************************\n");
printf("May you have a good time!!\nBye bye!!\n");
printf("***********************************\n");
getch();
return 0;
}
double change(char s[],int *st)/*从字符串s中读取一个数，st是在s上的游标*/
/*即从st开始读出一个数，如果读不出来则返回0*/
{
int count,q=1;
char tm[maxl]=" ";
if ((s[*st]=='-')&&(importance[s[(*st)-1]]>(-3)))
{
q=-1;
++(*st);
}
for (count=0;((s[*st]<='9')&&(s[*st]>='0'))||(s[*st]=='.');++(*st),++count)
tm[count]=s[*st];
tm[count]='\0';
--(*st);
return (atof(tm)*q);
}
void inim(int ck[])
{
ck['+']=1;
ck['-']=1;
ck['*']=2;ck['^']=3;
ck['/']=2;
ck['(']=10;
ck[')']=-1;
ck['#']=-2;
ck['a']=-3;ck[' ']=-3;ck['.']=-3;
ck['1']=-3;ck['A']=-3;
ck['2']=-3;
ck['3']=-3; ck['7']=-3;
ck['4']=-3; ck['8']=-3;
ck['5']=-3; ck['9']=-3;
ck['6']=-3; ck['0']=-3;
}
void calit(double s1[],int *to1,char s2[],int *to2,char tem)/*解析表达式*/
{
for(;importance[s2[*to2]]>importance[tem];--(*to2))
{
if(s2[*to2]=='(')
{
return;
}
if((*to1)==0)
{
printf("what you have input was wrong,input again\n");
pointer=1;
return;
}
switch(s2[*to2])
{
case '+':
--(*to1);
s1[*to1]+=s1[(*to1)+1];
break;
case '-':
--(*to1);
s1[*to1]-=s1[(*to1)+1];
break;
case '*':
--(*to1);
s1[*to1]*=s1[(*to1)+1];
break;
case '/':
--(*to1);
if (s1[(*to1)+1]==0.0)
{
printf("0 is not a divisor,you must input again.\n");
pointer=1;
return;
}
else
{
s1[*to1]/=s1[(*to1)+1];
break;
}
case '^':
--(*to1);
if ((s1[*to1]==0)&&(s1[(*to1)+1]==0))
{
printf("0^0 is not legal,input again");
pointer=1;
return;
}
s1[*to1]=pow(s1[*to1],s1[(*to1)+1]);
break;
}
}
}
void nospace(char s[])/*去掉字符串中的空格*/
{
int temi,len,si;
len=strlen(s)-1;
for(temi=0,si=0;si<=len;++si)
{
if(s[si]!=' ')
{
s[temi++]=s[si];
}
}
s[temi]='\0';
}
int kuohao(char s[],int len)/*判断括号是否匹配，匹配返回0，不匹配返回1*/
{
int tem=0,count;
for (count=0;count<=len;++count)
{
if (s[count]=='(') ++tem;
if (s[count]==')') --tem;
if (tem<0) return 1;
}
if (tem>0) return 1;
return 0;
}
int shuzi(char ab[],int is)/*判断ab中存储的字符是否都是合法字符，合法返回0，否则返回1*/
{
int i;
for(i=0;i<=is;++i)
{
if (!importance[ab[i]]) return 1;
}
return 0;
}
