Brainfuck

Brainfuck.cpp

#include <iostream>
#include <fstream>
#include <filesystem>
#include <cstdint>
using namespace std;
using namespace std::tr2::sys;
size_t const msize = 0x100000;
void bf(path name, path input, path output) {
    ifstream file(name, ios::binary);
    ifstream inf(input, ios::binary);
    ofstream outf(output, ios::binary);
    size_t const fsize = file_size(name);
    char * const program = new char[fsize + 1];
    file.read(program, fsize);
    size_t msx = 0;
    for (size_t i = 0, ms = 0; i < fsize; ++i) {
        if (program[i] == '[') {
            ++ms;
            if (ms > msx) msx = ms;
        } else if (program[i] == ']') --ms;
    }
    size_t * const stack = new size_t[msx];
    size_t * const jump = new size_t[fsize];
    for (size_t i = 0, j = 0; i < fsize; ++i) {
        if (program[i] == '[') {
            stack[j++] = i;
        } else if (program[i] == ']') {
            jump[i] = stack[--j];
            jump[stack[j]] = i;
        }
    }
    delete stack;
    uint8_t * const memory = new uint8_t[msize];
    for (size_t p = 0, m = 0;;) {
        switch (program[p]) {
        case '>':
            ++m;
            break;
        case '<':
            --m;
            break;
        case '+':
            ++memory[m];
            break;
        case '-':
            --memory[m];
            break;
        case ',':
            memory[m] = static_cast<uint8_t>(inf.get());
            break;
        case '.':
            outf.put(memory[m]);
            break;
        case '[':
            if (!memory[m]) p = jump[p];
            break;
        case ']':
            if (memory[m]) p = jump[p];
            break;
        case '\0':
            delete[] program;
            delete[] memory;
            delete[] jump;
            return;
        default:
            break;
        }
        ++p;
    }
}
int main() {
    bf("program.bf", "input.txt", "output.txt");
}