Reference no: EM131740239 , Length: 1

Apply the following algorithms in c++:

1- Converting an expression from infix to postfix

opstk= the empty stack;
while (not end of input) {
symb=next input character;
if (symb is an operand)
add symb to the postfix string
else {
while (!empty()&&prcd(stacktop(), symb)) {
topsym=pop();
add topsymbto the postfix string;
} /*end while*/
if (empty() II symb != ‘)')
push(symb);
else /* pop the open parenthesis and discard it */
topsymb= pop();
} /* end else*/
} /* end while*/
/*output any remaining operators*/
while (!empty()) {
topsymb=pop();
add topsymb to the postfix string;
} /* end while*/

2- Evaluating a postfix expression

Opndstk= the empty stack;
/* scan the input string reading one element at a time into symb*/
while (not end of input) {
symb=next input character;
if (symb is an operand)
push(symb);
else{
/* symb is an operator*/
opnd2=pop();
opnd1=pop();
value=resulr of applying symb to opnd1 and opnd2;
push(value);
} /* end else*/
} /* end while*/
return (pop());