Databases
StackOverflow2013
Postsdbo
POUsing a stack to determine if an expression has balanced parentheses
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POUsing a stack to determine if an expression has balanced parentheses
    primarykey
    data
    text
    <p>I am working on my last school assignment for the semester and we are being introduced to stacks for the first time but I am having an issue with my program not analyzing the expression properly. Everything executes but the program always comes out with the result that expression is unbalanced. Any clues to point me in the right direction?</p> <pre><code>// // main.cpp // Balanced Parenthesis #include "StringStack.h" #include &lt;iostream&gt; using namespace std; int main () { StringStack stack; char entry; int parCounter = 0; cout &lt;&lt; "This program will accept a string and determine whether it has balanced parenthesis.\n"; cout &lt;&lt; "Please type a sentence to be analyzed\n"; while (cin.get (entry) &amp;&amp; entry != '\n') { stack.push(entry); } if (stack.isEmpty()) { cout &lt;&lt; "The stack is empty./n"; } else{ stack.pop(entry); if (entry == ')') { parCounter++; } else if(entry == '('){ parCounter--; } } if (parCounter &gt; 0 || parCounter &lt; 0){ cout &lt;&lt; "This expression has UNBALANCED parentheses\n"; } else { cout &lt;&lt; "This expression has BALANCED parentheses\n"; } return 0; } // StringStack.h // Balanced Par #include &lt;iostream&gt; using namespace std; #ifndef StringStack_h #define StringStack_h //Define our stack class and its contents class StringStack { private: char *stackArray; int stackSize; char top; public: StringStack(); ~StringStack() {delete[] stackArray;} void push(char); void pop(char &amp;); bool isBalanced(); bool isEmpty(); }; #endif //Constructor StringStack::StringStack() { stackArray = new char[stackSize]; top = 0; } //Function to determine if stack is empty. bool StringStack::isEmpty() { if (top == 0) return true; else return false; } //Function to push letters/puncuation onto the stack void StringStack::push(char letter) { //if (isEmpty()) { top++; stackArray[top] = letter; } //else //{ //exit(1); //} } //Function to pop letters/puncuation off the stack void StringStack::pop(char &amp;letter) { if (isEmpty()) { cout &lt;&lt; "The stack is empty.\n"; exit(1); } else { letter = stackArray[top]; top--; } } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USEdison Gustavo Muenz
    1. USMageneto
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POUsing a stack to determine if an expression has balanced parentheses
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYou shouldn't be using the stack to store the entire input string itself. Your algorithm can be bettered. Since it's your assignment, I'll let you think over it.
      singulars
      1. POUsing a stack to determine if an expression has balanced parentheses
      1. USvrk001
    2. COWhere is the definition of StringStack::isBalanced method? On the other hand, you having the same number of '(' and ')'n don't ensure balanced parentheses.
      singulars
      1. POUsing a stack to determine if an expression has balanced parentheses
      1. USRaydel Miranda
    3. COI recommend you read some doc about **infix** and **postfix** expressions and then rewrite your code in order to do it the right way.
      singulars
      1. POUsing a stack to determine if an expression has balanced parentheses
      1. USRaydel Miranda
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload