p2

#include <iostream>
#include <string>
using namespace std;
enum State {
S0, S1, S2
};
bool isDivisibleBy3(const string& input) {
State currentState = S0; // Start in state S0 (remainder = 0)
for (char c : input) {
switch (currentState) {
case S0:
if (c == '0') {
currentState = S0; // Stay in S0 (remainder 0)
} else if (c == '1') {
currentState = S1; // Move to S1 (remainder 1)
}
break;
case S1:
if (c == '0') {
currentState = S2; // Move to S2 (remainder 2)
} else if (c == '1') {
currentState = S0; // Move to S0 (remainder 0)
}
break;
case S2:
if (c == '0') {
currentState = S1; // Move to S1 (remainder 1)
} else if (c == '1') {
currentState = S2; // Stay in S2 (remainder 2)
}
break;
}
}
// Accept if the FSM ends in state S0 (remainder 0, divisible by 3)
return currentState == S0;
}
int main() {
string input;
cout << "Enter a binary string: ";
cin >> input;
if (isDivisibleBy3(input)) {
cout << "Accepted (the number is divisible by 3)" << endl;
} else {
cout << "Rejected (the number is not divisible by 3)" << endl;
}
return 0;
}