#include <iostream>
#include <vector>
#include <set>
#include <stack>
using namespace std;

// Function to compute the epsilon closure of a state
set<int> epsilonClosure(vector<vector<int>> &nfa, int state) {
    stack<int> s;
    set<int> visited;
    s.push(state);
    visited.insert(state);
    while (!s.empty()) {
        int curr = s.top();
        s.pop();
        for (int i = 0; i < nfa[curr].size(); i++) {
            int next = nfa[curr][i];
            if (next == -1 || visited.count(next)) continue;
            visited.insert(next);
            s.push(next);
        }
    }
    return visited;
}

// Function to compute the epsilon closure of a set of states
set<int> epsilonClosure(vector<vector<int>> &nfa, set<int> states) {
    set<int> result;
    for (auto state : states) {
        set<int> closure = epsilonClosure(nfa, state);
        result.insert(closure.begin(), closure.end());
    }
    return result;
}

int main() {
    // Example NFA with epsilon moves
    vector<vector<int>> nfa = {
        {1, 2, -1},
        {3, -1},
        {4, -1},
        {5, 6},
        {7, -1},
        {8, -1},
        {9, -1},
        {10, 11},
        {12, -1},
        {13, -1},
        {14, -1},
        {-1},
    };

    // Compute the epsilon closure of state 0
    set<int> closure = epsilonClosure(nfa, 0);

    // Print the epsilon closure
    cout << "Epsilon closure of state 0: { ";
    for (auto state : closure) {
        cout << state << " ";
    }
    cout << "}" << endl;

    // Compute the epsilon closure of states {0, 1, 2}
    set<int> states = {0, 1, 2};
    closure = epsilonClosure(nfa, states);

    // Print the epsilon closure
    cout << "Epsilon closure of states {0, 1, 2}: { ";
    for (auto state : closure) {
        cout << state << " ";
    }
    cout << "}" << endl;

    return 0;
}

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}