C语言编写四则运算

1、C语言编写四则运算#include<stdio.h>/计算器#include<malloc.h>#defineSTACKSIZE100/maxsizeofthestack#defineSTACK_INCREMENT/reallocsizetypedefstructFStack/stackofintfloat*base;float*top;intstacksize;FStack;voidInit(FStack*s)sizeof(FStack);sizeof(FStack);s->base=(float*)malloc(STACK_SIZEif(!s->base

2、)printf("overflow!n");return;s->top=s->base;s->stacksize=STACK_SIZEboolisEmpty(FStack*s)if(s->top=s->base)returntrue;elsereturnfalse;voidPush(FStack*s,floate)if(s->top-s->base>=s->stacksize)printf("stackisfull!nrealloc%dn",STACK_INCREME；NTs->base=(fl

3、oat*)realloc(s->base,(s->stacksize+sizeof(FStack);if(!s->base)printf("overflow!n");return;s->top=s->base+s->stacksize;s->stacksize+=STACK_INCREMENT*(s->top)=e;(s->top)+;floatGetTop(FStack*s)if(s->top=s->base););printf("stackisempty!n"return0;float

4、e=*(s->top-1);returne;voidPop(FStack*s)if(s->top=s->base)printf("stackisempty!n"return;s->top-;typedefstructCStack/stackofcharchar*base;char*top;intstacksize;CStack;voidInit(CStack*s)s->base=(char*)malloc(STACK_SIZEsizeof(CStack);if(!s->base)printf("overflow!n")

5、;return;s->top=s->base;s->stacksize=STACK_SIZEboolisEmpty(CStack*s)if(s->top=s->base)returntrue;elsereturnfalse;voidPush(CStack*s,inte)if(s->top-s->base>=s->stacksize)printf("stackisfull!nrealloc%dn",STACK_INCREME；NTs->base=(char*)realloc(s->base,(s->sta

6、cksize+sizeof(CStack);if(!s->base)printf("overflow!n");return;s->top=s->base+s->stacksize;s->stacksize+=STACK_INCREMENT*(s->top)=e;(s->top)+;charGetTop(CStack*s)if(s->top=s->base)printf("stackisempty!'n");return0;chare=*(s->top-1);returne;voidPop

7、(CStack*s)if(s->top=s->base)printf("stackisempty!n"return;);s->top-;boolisOper(charch)if(ch='+'|ch='-'|returntrue;elsech='*'|ch='/'|ch='%')returnfalseintPriority(charch)intp;switch(ch)case'(':p=0;break;case'+':case'-'

8、:p=1;break;casecase7'case'%':p=2;break;returnp;floatCalculate(floatfl,floatf2,charoper)floatf3;switch(oper)case'+':f3=f1+f2;break;case'-':f3=f1-f2;break;case'*':f3=f1*f2;break;case'%':f3=(float)(int)f1%(int)f2);break;case'/':if(f2=0)printf("nD

9、evidedbyzero!");exit(1);elsef3=f1/f2;break;returnf3;floatStrtoFloat(char*str,int*pos)floatfRes;inti=*pos;intk;charn50;for(k=0;stri>='0'&&stri<=9|stri='.'i+,k+)nk=stri;nk='0'*pos=i;fRes=atof(n);returnfRes;boolCheckfchar*str)inti=0;while(stri!='0')if(

10、stri!='+'&&stri!='-'&&stri!='*'&&stri!='/'&&stri!='%'&&stri!='.'&&stri!='('&&stri!=')'&&(stri<'0'|stri>9)returnfalse;i+;returntrue;voidmain()charexp100;inti;f

11、loatf,f1,f2;charoper;FStackfstack;CStackcstack;Init(&fstack);Init(&cstack);printf("Theexpressionis:");gets(exp);if(!Check(exp)printf("inputerror!exitnow!n");exit(1);for(i=0;expi!='0'&&expi!=-52;i+)if(!isOper(expi)f=StrtoFloat(exp,&i);Push(&fstack,f

12、);if(isOper(expi)if(!isEmpty(&cstack)while(!isEmpty(&cstack)&&Priority(expi)<=Priority(GetTop(&cstack)oper=GetTop(&cstack);Pop(&cstack);f2=GetTop(&fstack);Pop(&fstack);f1=GetTop(&fstack);Pop(&fstack);f=Calculate(f1,f2,oper);Push(&fstack,f);Push(&

13、;cstack,expi);elsePush(&cstack,expi);elseif(expi='(')Push(&cstack,expi);elseif(expi=')')while(GetTop(&cstack)!='('&&!isEmpty(&cstack)oper=GetTop(&cstack);Pop(&cstack);f2=GetTop(&fstack);Pop(&fstack);f1=GetTop(&fstack);Pop(&fstack);f=Calculate(f1,f2,oper);Push(&fstack,f);Pop&cstack);while(!isEmpty(&cstack)oper=GetTop(&cstack);P