In any language program mostly syntax error occurs due to unbalancing delimiter such as (),{},[]. Write C++ program using stack to check whether given expression is well parenthesized or not.

#include<iostream>
#include<string.h>
using namespace std;
class braces
{    char st[20];
  int top;
   public:
     void push(char a);
     void pop();
     void input();
   
};
void braces::push(char a)
{      top++;   st[top]=a;                 }
void braces::pop()
{        top--;                        }
void braces::input()
{   char ch[20];  int x=1,i=0;
     top=-1;
    cout<<"\nenter the expression";
     cin>>ch;
      while(i<strlen(ch))
      {   
     
   if((ch[i]=='{')||(ch[i]=='[')||(ch[i]=='('))
     {     push(ch[i]);                           }
      
         if(ch[i]=='}')
     {    if(st[top]=='{')
            pop();
         else
         {   
                 cout<<"\n matching opening brace '{' is not found";   
              
            
          }
          
     }
     if(ch[i]==']')
     {    if(st[top]=='[')
            pop();
       else
       {    
          cout<<"\n matching  brace '[' is not found";
          
           }
     }
      if(ch[i]==')')
     {    if(st[top]=='(')
            pop();
       else
       { 
          cout<<"\n matching opening brace '(' is not found";
        
         } 
     }
     i++;
      }
        if(top==-1)
        {   x=5; 
           cout<<"\nstack is empty";
           cout<<"\n EXPRESSION IS WELL PARENTHESIZED";
         
       }
        else
        {   while(top!=-1)
            {
            if(st[top]=='[')
            { pop();  cout<<"\n matching closing brace ']' is not found";   }
            if(st[top]=='{')
            { pop();  cout<<"\n matching closing brace '}' is not found";   }
            if(st[top]=='(')
            { pop();  cout<<"\n matching closing brace ')' is not found";   }
            }
           
             cout<<"\n EXPRESSION IS NOT WELL PARENTHESIZED";
       }
  
           
     
}

     int main()
     {    braces c;
          c.input();
     
       }