int main()
{
int x,y,n,result,size;
STACK <char, 10> A;
string expression;
// clear stack
A.Clear();
// get expression from user
cout << "Enter a postfix expression:";
cin >> expression;
size = expression.length();
char item[size];
for(int i=0; i<size; ++i){
item[i] = expression[i];
}
for(int j=0; j<size; ++j){
if(item[j] == '+'){
x = A.Pop();
y = A.Pop();
A.Push(y+x);
}
else if( item[j] == '*'){
x = A.Pop();
y = A.Pop();
A.Push(y*x);
}
else if( item[j] == '/'){
x = A.Pop();
y = A.Pop();
A.Push(y/x);
}
else if( item[j] == '-'){
x = A.Pop();
y = A.Pop();
A.Push(y-x);
}
else{
n = (item[j]) - (48);
A.Push(n);
}
}
// output result
result = A.Pop();
cout << "Result is " << result << endl;
return(0);
}
int main()
{
int x,y,n;
STACK <char, 10> A;
char item[10];
// clear stack
A.Clear();
// get expression from user
cout << "Enter a postfix expression with $ at the end: ";
cin.getline(item,10);
// process data
while(strcmp(item, "$") != 0)
{
if(strcmp(item, "+") == 0)
{
x = A.Pop();
y = A.Pop();
A.Push(y+x);
}
else if(strcmp(item, "*") == 0)
{
x = A.Pop();
y = A.Pop();
A.Push(y*x);
}
else if(strcmp(item, "/") == 0)
{
x = A.Pop();
y = A.Pop();
A.Push(y/x);
}
else if(strcmp(item, "-") == 0)
{
x = A.Pop();
y = A.Pop();
A.Push(y-x);
}
// if its a number
else
{
n = atoi(item);
A.Push(n);
}
}
int r = A.Pop();
// output result
cout << "Result is " << r << endl;
return(0);
}
