C++ ProgrammingActivity: Linked List Stack and BracketsExplain the flow of the main code not necessarily every line, as long as you explain what the important parts of the code do. The code is already correct, just explain the flowSEE ATTACHED PHOTO FOR THE PROBLEM INSTRUCTIONSint main(int argc, char** argv) { SLLStack* stack = new SLLStack(); int test; int length; string str; char top; bool flag = true; cin >> test; switch (test) { case 0: getline(cin, str); length = str.length(); for(int i = 0; i < length; i++){ if(str[i] == '{' || str[i] == '(' || str[i] == '['){ stack->push(str[i]); } else if (str[i] == '}' || str[i] == ')' || str[i] == ']'){ if(!stack->isEmpty()){ top = stack->top(); if(top == '{' && str[i] == '}' || top == '(' && str[i] == ')' || top == '[' && str[i] == ']'){ stack->pop(); } else { cout << "not accepted"; flag = false; break; } } else { cout << "not accepted" << endl; flag = false; break; } } } if(flag == true){ if(!stack->isEmpty()) { cout << "not accepted"; } else { cout << "accepted"; } } break; Additionally, you are also going to solve the Brackets Problem inthe case O of the main.cpp file where you have to identifywhether a given string that contains brackets is valid or not.Brackets may be parentheses ( and ), curly brackets { and },and square brackets [ and ]. Each opening symbol must matchits corresponding closing symbol. For example, a left bracket,"L" must match a corresponding right bracket, "]," as in thefollowing expression: [(0]Take note of the three considerations that will make the stringinvalid: a mismatch where the closing bracket did not matchwhat was in the top of the stack (e.g. "(1)"), an excess openingwhere we have completed checking the string where thereshould have been more closing bracket/s (e.g. "(0"), and anexcess closing where we found a closing bracket but there's noopening bracket to match it with (e.g. "0)").Using the methods of a stack and your SLL implementation,create a separate program that will print accepted if a givenstring is valid exclusively in terms of brace pairing andotherwise, print not accepted.InputFor SLLStack Implementation (case 1+): Don't CareFor Braces Implementation (case 0): A string of brackets

As you asked for the explanation only I am writing the explanation in comment form. after // you'll…

C++ Programming Activity: Linked List Stack and Brackets Explain the flow of the main code not necessarily every line, as long as you explain what the important parts of the code do. The code is already correct, just explain the flow SEE ATTACHED PHOTO FOR THE PROBLEM INSTRUCTIONS int main(int argc, char** argv) { SLLStack* stack = new SLLStack(); int test; int length; string str; char top; bool flag = true; cin >> test; switch (test) { case 0: getline(cin, str); length = str.length(); for(int i = 0; i < length; i++){ if(str[i] == '{' || str[i] == '(' || str[i] == '['){ stack->push(str[i]); } else if (str[i] == '}' || str[i] == ')' || str[i] == ']'){ if(!stack->isEmpty()){ top = stack->top(); if(top == '{' && str[i] == '}' || top == '(' && str[i] == ')' || top == '[' && str[i] == ']'){ stack->pop(); } else { cout << "not accepted"; flag = false; break; } } else { cout << "not accepted" << endl; flag = false; break; } } } if(flag == true){ if(!stack->isEmpty()) { cout << "not accepted"; } else { cout << "accepted"; } } break;