中缀表达式变后缀表达式算法

?lf((x1=gettopqstack(s))==NIL) ?:?exit(O);

?while(1)

?if(x2!='+'&& x2!='?'&& x2!=*&&

x2!=7'&& x2!=t(t && x2!=')' && x2!='#') ?{ printf("％ c",x2);

?x2=expression[++j];

?:?)

?:?else if(proceed(x1,x2)==t

?:?e xit(O);

?:?if((x1=gettopqstack(s))==NIL) ?:?e xit(O);

?x2= expression[++j];

?:?)

?else if(proceed(x1,x2)==t>t)

?{if((x=popqstack(s))==NIL)

?:?exit(O);

?printf("％c”,x);

?if((x1 =gettopqstack(s))==NIL)

?:?exit(O);

.:?}

?else if(proceed(x1 ,x2)==-{&& x仁'('&& x2=')')

?{if(popqstack(s)==NIL)

?:?exit(O);

?if((x1 =gettopqstack(s))==NIL)

?:?exit(O);

?x2= expression[++j];

.:?}

?else if(proceed(x1 ,x2)==-c&& x仁# && x2=#)

?{ return 1;

.:?)

?else if(proceed(x1,x2)==c')

?break;

?:?}

?Printf(An错误！” )；

?return 0;

?:?proceed(x1,x2)完成算符比较功能?char proceed(char x1 ,char x2)

?Midstring[0]=x2;

?:?midstring[1]=t\0,;

?:?if(((x1=='+'||x1='?')&&strstr("+?)#,,,midstring)!=NULL||

((x1=*||x 仁'/')&&strstr("+?*/)#”,midstring)!=NULL)

||(x1 ==')')&&strstr("+?

*/)#”,midstring)!=NULL)) .:?{

?result。'；

?Else if((x1==t&&x2==y)|| ?(x1==*&& x2=#))?:.{

?result—;

.:?)

?Else if((x1 ='('&& x2==#)|| ?(x1==t),&& x2=t(,)|| ?:?(x1==t#,&&x2==t)>)) ?{ result^'

?Return result;

.:?}

?:?主函数如下：

"include