doing testing on the function. I think is that is there any ways for the data types to store both the character or integers instead of using int for integers only and char for character only. This is my biggest problem.Because my function store only 2 int with a operator sign, what should I do if I had 2 operators, 3 operands, Then 3 operators, 4 operands, not possible to store all in so many functions. Seriously this is very difficult.
Another version, trying to do something like more than 2 operators, but still give error if i try to do this 2 3 + gives 6 instead of 5.Code:#include <iostream> #include <stack> void calculation(int &ope1, int &ope2, char &input); using namespace std; stack <int> a; void main(void) { bool check = false; int number; char ch; char oper; while (!check) { cout << "Press # for numbers: " ; cout << "Press your sign for calculation." ; cin >> ch; if (ch == '#') { cout << "Enter number; "; cin >> number; a.push(number); } else if (ch != '#') { calculation(number, number, ch); check = true; } } cout << a.top(); system ("pause"); } void calculation(int &oper1, int &oper2, char &chr) { switch (chr) { case '+': a.push(oper1 + oper2); break; case '-': a.push(oper1 - oper2); break; case '*': a.push(oper1 * oper2); break; case '/': a.push(oper1 / oper2); break; } }
Another version. Able to input numbers, operators. (no error checking. ) But the calculation completely wrong. Where is the wrong part.Code:#include <iostream> #include <stack> void calculation(int &ope1, int &ope2, char &input); using namespace std; stack <int> a; void main(void) { bool check = false; int number; char ch; char oper; while (!check) { cout << endl; cout << "Press # for numbers: " << endl; cout << "Press your sign (+, -, /, * ) for calculation." << endl ; cout << "press '=' to print the calculation." ; cin >> ch; if (ch == '#') { cout << "Enter number; "; cin >> number; a.push(number); } else if (ch != '#') { calculation(number, number, ch); if (ch == '=') { check = true; } else if (ch != '=') { check = false; } } } cout << "Your value is " << a.top() ; system ("pause"); } void calculation(int &oper1, int &oper2, char &chr) { switch (chr) { case '+': a.push(oper1 + oper2); break; case '-': a.push(oper1 - oper2); break; case '*': a.push(oper1 * oper2); break; case '/': a.push(oper1 / oper2); break; } }
Where are all your pop() calls?
The whole idea of RPN is that
a) when you see a number, you push it onto the stack
b) when you see an operator, you pop some arguments, calculate and push the result.
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Added a pop() calls but still the answer remain the same. Just wonder how on earth the calculation always give me very funny value.Code:#include <iostream> #include <stack> void calculation(int &ope1, int &ope2, char &input); using namespace std; stack <int> a; int main() { bool check = false; int number; char ch; char oper; while (!check) { cout << endl; cout << "Press # for input numbers: " << endl; cout << "Press your sign (+, -, /, * ) for calculation." << endl ; cout << "press '=' to print the calculation." ; cin >> ch; if (ch == '#') { cout << "Enter number; "; cin >> number; a.push(number); } else if (ch != '#') { calculation(number, number, ch); if (ch == '=') { check = true; } else if (ch != '=') { check = false; } } } cout << "Your value is " << " " << a.top() ; system ("pause"); return 0; } void calculation(int &oper1, int &oper2, char &chr) { switch (chr) { a.pop(); case '+': a.push(oper1 + oper2); //a.pop(); break; case '-': a.push(oper1 - oper2); //a.pop(); break; case '*': a.push(oper1 * oper2); //a.pop(); break; case '/': a.push(oper1 / oper2); //a.pop(); break; } }
pop()
Hey, where did that value go?
Did you even read my previous post, or did you just gloss over it and throw in some pop statements for the hell of it.
Perhaps if you made your function
calculation(ch);
it would force you to THINK about where the operands are coming from.
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
How to do it such that the program knows see the number, it would be push. If it is a charcter, the program would pop the argument,
Each variables have different data types, not possible to check if it was a char or int. Cant do like (while !ch) Cant possibly check the variables using cinCode:int number; char ch; while (!cin >> ch) //how to code { cin >> number; }
Last edited by evildotaing; 01-03-2012 at 02:42 AM.
if i do this, how am i going to do the calculation without the 2 valueCode:calculation(ch);
Read as a string, then check and parse.Originally Posted by evildotaing
Look up a C++ Reference and learn How To Ask Questions The Smart Way
Thought string only use for words, sentence
Look at my post#35, i try to do the other way by input # if the user want to include a number, and the operator sign for calculation, it gives funny value.
Well, you will only be reading as a string. After parsing, you still have numbers to work with.
Look up a C++ Reference and learn How To Ask Questions The Smart Way
cin >> string
If lets say user press 6 4 + in a string
How to check if the string that was input is the number or charcters, because string is grouped together.
[code]
You'll be reading 3 tokens as string: "6", "4" and "+". One approach is to check the first character of the string: '6' is not '+', '-' or some other operator, so you attempt to parse it as a number, e.g., as an int. The parsing succeeds, so you store 6 in the stack, and move on to "4".
Look up a C++ Reference and learn How To Ask Questions The Smart Way
Should I do it like asking user to enter any input in a string." Or should I use character arrays.Code:#include <iostream> #include <stack> #include <string> void calculation(int &ope1, int &ope2, char &input); using namespace std; stack <int> a; int main() { string post; cout << "Enter your expression: " << endl; cin >> post; getline(cin , post); cout << post; system ("pause"); }
