Brainfudge Interpreter

brainfudge-interpreter.cpp

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

void Interpret(string input, vector<uint8_t> &memory);

int main()
{
    vector<uint8_t> memory{ 0 };
    string input;

    getline(cin, input);
    Interpret(input, memory);
}

void Interpret(string input, vector<uint8_t> &memory)
{
    vector<unsigned int> loops;
    int pointer = 0;

    for (size_t i = 0; i < input.length(); ++i) {
        char c = input[i];

        switch (c) {
            case '>':
                if (++pointer > memory.size() - 1) {
                    memory.push_back(0);
                }
                break;
            case '<':
                if (--pointer < 0) {
                    cout << "Error";
                    return;
                }
                break;
            case '+':
                ++memory[pointer];
                break;
            case '-':
                --memory[pointer];
                break;
            case '.':
                cout << (char) memory[pointer];
                break;
            case ',':
                char programInput;
                cin >> programInput;
                memory[pointer] = (uint8_t) programInput;
                break;
            case '[':
                if (memory[pointer] == 0) {
                    unsigned int simLoops = 1;
                    unsigned int simIndex = i + 1;

                    while (simLoops > 0 && simIndex < input.length()) {
                        char a = input[simIndex];

                        if (a == ']') {
                            simLoops--;
                        } else if (a == '[') {
                            simLoops++;
                        }

                        simIndex++;
                    }

                    i = simIndex - 1;
                } else {
                    loops.push_back(i);
                }
                break;
            case ']':
                if (loops.size() > 0) {
                    if (memory[pointer] == 0) {
                        loops.pop_back();
                    } else {
                        i = loops[loops.size() - 1];
                    }
                }
                break;
        }
    }
}