Little Brainfuck Executor

brainfuck-1.cpp

#include <bits/stdc++.h>
using namespace std;
int cursor = 0, size, cmd_cursor = 0, loopIndex = 0;
string version = "v0.1.1";
void exe(string cmd), start();
void start(){
    printf("You got into Brain Fuck compiler.\n");
    printf("This software helps you to run Brain Fuck codes.\n");
    printf("Now version : %s\n", version.c_str());
    printf("Chars & its meanings : \n");
    printf("\t >  - move cursor to next memory.\n");
    printf("\t <  - move cursor to previous memory.\n");
    printf("\t +  - increase the value of the current memory by 1.\n");
    printf("\t -  - decrease the value of the current memory by 1.\n");
    printf("\t .  - print the value of the current memory in ASCII.\n");
    printf("\t[ ] - enter a loop and break while the value of current memory is 0.\n");
}
int main(int argc, char *argv[]){
    if(argc == 1){
        start();
        printf("Set a max size of your memory(max:100000): ");
        scanf("%d", &size);
        printf("Memory settings successed, your memory is about %d size.\n", size);
        printf("Input you Brain Fuck codes in one line:\n");
        string cmd; cin >> cmd;
        exe(cmd);
    }else{
        size = 1000;
        string cmd(argv[1]);
        exe(cmd);
    }
    return 0;
}
void exe(string cmd){
    unsigned short mem[size]; // 内存
    memset(mem, 0, sizeof(mem)); // 内存清零
    int loopStart = -1; // 循环开始
    bool looping = false; // 是否在循环
    for(int i = 0; i < cmd.length(); ++ i){
        switch(cmd[i]){
            case '>': cursor ++; break; // 指针右移
            case '<': cursor --; break; // 指针左移
            case '+': // 内存值加一
                if(cursor >= 0 && cursor < size){
                    mem[cursor] ++;
                    if(mem[cursor] == 256) mem[cursor] = 0;
                }else return;
                break;
            case '-': // 内存值减一
                if(cursor >= 0 && cursor < size){
                    mem[cursor] --;
                    if(mem[cursor] == -1) mem[cursor] = 255;
                }else return;
                break;
            case '.': // 输出内存
                printf("%c", (char)mem[cursor]);
                break;
            case '[': // 开始循环
                loopStart = i;
                looping = true;
                break;
            case ']': // 结束循环
                if(mem[cursor] == 0) looping = false;
                else i = loopStart;
                break;
            case '$': // 聚合
                
                break;
        }
    }
    printf("\n");
    return;
}

brainfuck-2.cpp

#include<iostream>
#include<cstring>
const int MAXSIZE = 100000;
using namespace std;
void parse(char*, int&, int&, char*, int*);
int main(){
    char str[MAXSIZE];
    int rel[MAXSIZE];
    int pos = 0;
    int ptr = 0;
    char arr[MAXSIZE];
    memset(str, 0, sizeof(str));
    memset(arr, 0, sizeof(arr));
    memset(rel, 0, sizeof(rel));
    char flag;
    int i = 0;
    while(flag != EOF){
        flag = getchar();
        str[i++] = flag;
    }
    int l = 0, end = strlen(str);
    while (l!=end){
        while (l<end && str[l++] != '[');
        auto r = l;
        int count = 1;
        for (; r < end; r++){
            if (str[r] == '[')count++;
            if (str[r] == ']'){
                count--; if (count == 0){
                    r++; break;
                }
            }
        };
        rel[l - 1] = r-1; rel[r - 1] = l-1;
    }
    while (str[pos] != '\0'){
        parse(str, pos, ptr, arr, rel);
        pos++;
    }
 
    return 0;
}
 
void parse(char* str, int& pos, int &ptr, char *arr, int *rel){
    switch (str[pos]){
        case '>':
            ptr++; break;
        case '<':
            ptr--; break;
        case '+':
            arr[ptr]++;
            if(arr[ptr] == 256) arr[ptr] = 0;
            break;
        case '-':
            arr[ptr]--;
            if(arr[ptr] == -1) arr[ptr] = 255;
            break;
        case '.':
            putchar(arr[ptr]);
            break;
        case ',':
            arr[ptr] = getchar();
            break;
        case '[':
            if (!arr[ptr])pos = rel[pos]; break;
        case ']':
            pos = rel[pos]-1; break;
        default:
            break;
    }
}