post fix

#include
#include
#include
const int MAX=50;
class postfix
{
private:
char stack[MAX][MAX],target[MAX];
char temp1[2],temp2[2];
char str1[MAX],str2[MAX],str3[MAX];
int i,top;
public:
postfix();
void setexpr(char *c);
void push(char *str);
void pop(char *a);
void convert();
void show();
};
postfix::postfix()
{
i=0;
top=-1;
strcpy(target," ");
}
void postfix::setexpr(char *c)
{
strcpy(target,c);
}
void postfix::push(char *str)
{
if(top==MAX-1)
cout<else
{
top++;
strcpy(stack[top],str);
}
}
void postfix::pop(char *a)
{
if(top==-1)
cout<else
{
strcpy(a,stack[top]);
top--;
}
}
void postfix::convert()
{
while(target[i])
{
if(target[i]==' ')
i++;
if(target[i]=='%'||target[i]=='*'||target[i]=='-'||target[i]=='+'||target[i]=='/'|target[i]=='$')
{
pop(str2);
pop(str3);
temp1[0]=target[i];
temp1[1]='\0';
strcpy(str1,str3);
strcat(str1,temp1);
strcat(str1,str2);
push(str1);
}
else
{
temp1[0]=target[i];
temp1[1]='\0';
strcpy(temp2,temp1);
push(temp2);
}
i++;
}
}
void postfix::show()
{
char *t;
t=stack[0];
while(*t)
{
cout<<" "<<*t;
t++;
}
cout<}
void main()
{
clrscr();
char expr[MAX];
cout<<"\n enter an expression in postfix form:";
cin.getline(expr,MAX);
postfix q;
q.setexpr(expr);
q.convert();
cout<<"\n the infix expression is:";
q.show();
getch();
}