急 用算符优先法对算术表达式求值的过程 if(c==35||(c>=40&&c<=43)||c==45||(c>=47&&c<=57))什么意思

Question

char m[7]="+-*/()#";

char n[7][7]={">><<<>>",">><<<>>",">>>><>>",">>>><>>","<<<<<= "
,">>>> >>","<<<<< ="};
char Precede(char a,char b){
int i=0,j=0;
while(m[i]!=a)
i++;
while(m[j]!=b)
j++;
return(n[i][j]);
}
float Operate(float a,char theta,float b){
float r;
switch(theta){
case'+':r=a+b;break;
case'-':r=a-b;break;
case'*':r=a*b;break;
case'/':if(b!=0)r=a/b;
else printf("输入错误!");
break;
}
return r;
}
void main(){
SqStack_T OPTR;
SqStack_N OPND;
float a,b,i;
char theta,c,x;
InitStack_T(&OPTR);Push_T(&OPTR,'#');
InitStack_N(&OPND);
printf("请输入表达式并以'#'结尾:\n");
c=getchar();
if(c==35||(c>=40&&c<=43)||c==45||(c>=47&&c<=57))
{
while(c!='#'||GetTop_T(&OPTR)!='#')
{
if(c>=48&&c<=57)
{
i=(float)c-48;
Push_N(&OPND,i);
c=getchar();
}
else
{
switch(Precede(GetTop_T(&OPTR),c))
{
case'<':Push_T(&OPTR,c);c=getchar();break;
case'=':x=Pop_T(&OPTR);c=getchar();break;
case'>':theta=Pop_T(&OPTR);b=Pop_N(&OPND);
a=Pop_N(&OPND);
Push_N(&OPND,Operate(a,theta,b));break;
}
}
}printf("结果是%f\n",GetTop_N(&OPND));
}
else printf("输入错误!\n");
}

Answer 1

if(c==35||(c>=40&&c<=43)||c==45||(c>=47&&c<=57))

检验c是不是35，40到43，45，47到57中的任何一个数