AoC2022_Day22/main.cpp

#define OLC_PGE_APPLICATION
#include "pixelGameEngine.h"
#include "olcutils.h"

using namespace olc;

enum Direction{
    RIGHT,
    DOWN,
    LEFT,
    UP
};

struct Instruction{
    int number=-1;
    Direction turn;
};

int main()
{
    std::vector<std::vector<char>>map;
    std::vector<Instruction>instructions;
    std::vector<vi2d>visitedLocs;
    std::ifstream file("input");
    while (file.good()){
        std::string line;
        std::getline(file,line);
        if (line.length()>0){
            if (line[0]=='.'||line[0]==' '||line[0]=='#'){
                std::vector<char>mapRow;
                for (int i=0;i<line.length();i++){
                    mapRow.push_back(line[i]);
                }
                map.push_back(mapRow);
            } else {
                //Parse the instruction set.
                bool isNumber=true;
                int marker=0;
                while(marker<line.length()){
                    if (isNumber){
                        std::string acc="";
                        while (line[marker]>='0'&&line[marker]<='9'){
                            acc+=line[marker++];
                        }
                        instructions.push_back({std::atoi(acc.c_str())});
                        isNumber=false;
                    } else {
                        switch(line[marker++]){
                            case 'R':{
                                instructions.push_back({-1,Direction::RIGHT});
                            }break;
                            case 'L':{
                                instructions.push_back({-1,Direction::LEFT});
                            }break;
                        }
                        isNumber=true;
                    }
                }
            }
        }
    }

    for (int y=0;y<map.size();y++){
        for (int x=0;x<map[y].size();x++){
            std::cout<<map[y][x];
        }
        std::cout<<std::endl;
    }
    std::cout<<"============="<<std::endl;
    for (int i=0;i<instructions.size();i++){
        if (instructions[i].number==-1){
            if (instructions[i].turn==Direction::RIGHT){
                std::cout<<'R';
            } else {
                std::cout<<'L';
            }
        } else {
            std::cout<<instructions[i].number;
        }
    }
    std::cout<<std::endl;

    vi2d pos={0,0};
    for (int i=0;i<map[0].size();i++){
        if (map[0][i]!=' '){
            pos={i,0};
        }
    }
    int instructionMarker=0;
    Direction facingDir=Direction::RIGHT;
    while (instructionMarker<instructions.size()){
        Instruction&instruction=instructions[instructionMarker];
        if (instruction.number!=-1){
            std::cout<<"Moving "<<instruction.number<<" steps"<<std::endl;
            int steps=instruction.number;
            while (steps>0){
                switch (facingDir){
                    case Direction::RIGHT:{
                        char tile=' ';
                        vi2d targetPos={pos.x+1,pos.y};
                        if (pos.x+1>=map[pos.y].size()){
                            for (int i=0;i<map[pos.y].size();i++){
                                if (map[pos.y][i]=='.'){
                                    targetPos.x=i;
                                    break;
                                } else 
                                if (map[pos.y][i]=='#'){
                                    //It's a dead end so we can't move. Go next.
                                    goto next;
                                }
                            }
                        }
                        tile=map[targetPos.y][targetPos.x];
                        switch (tile){
                            case '.':{
                                pos=targetPos;
                                visitedLocs.push_back(pos);
                            }break;
                            case '#':{
                                goto next;
                            }break;
                            case ' ':{
                                //Impossible when going right.
                            }break;
                        }
                    }break;
                    case Direction::LEFT:{
                        char tile=' ';
                        vi2d targetPos={pos.x-1,pos.y};
                        if (pos.x-1<0||map[pos.y][pos.x-1]==' '){
                            if (map[pos.y][map[pos.y].size()-1]=='.'){
                                targetPos.x=map[pos.y].size()-1;
                            } else 
                            if (map[pos.y][map[pos.y].size()-1]=='#'){
                                //It's a dead end so we can't move. Go next.
                                goto next;
                            }
                        }
                        tile=map[targetPos.y][targetPos.x];
                        switch (tile){
                            case '.':{
                                pos=targetPos;
                                visitedLocs.push_back(pos);
                            }break;
                            case '#':{
                                goto next;
                            }break;
                            case ' ':{
                                //Impossible when going right.
                            }break;
                        }
                    }break;
                    case Direction::UP:{
                        char tile=' ';
                        vi2d targetPos={pos.x,pos.y-1};
                        if (pos.y-1<0||map[pos.y-1][pos.x]==' '){
                            for (int y=map.size()-1;y>0;y--){
                                if (map[y].size()>pos.x){
                                    if (map[y][pos.x]=='.'){
                                        targetPos.y=y;
                                        break;
                                    }else
                                    if (map[y][pos.x]=='#'){
                                        goto next;
                                    }
                                }
                            }
                        }
                        tile=map[targetPos.y][targetPos.x];
                        switch (tile){
                            case '.':{
                                pos=targetPos;
                                visitedLocs.push_back(pos);
                            }break;
                            case '#':{
                                goto next;
                            }break;
                            case ' ':{
                                //Impossible when going right.
                            }break;
                        }
                    }break;
                    case Direction::DOWN:{
                        char tile=' ';
                        vi2d targetPos={pos.x,pos.y+1};
                        if (pos.y+1>=map.size()||map[pos.y+1].size()<=pos.x||map[pos.y+1][pos.x]==' '){
                            for (int y=0;y<map.size();y++){
                                if (map[y].size()>pos.x){
                                    if (map[y][pos.x]=='.'){
                                        std::cout<<"Found a spot. ("<<y<<")"<<std::endl;
                                        targetPos.y=y;
                                        break;
                                    }else
                                    if (map[y][pos.x]=='#'){
                                        std::cout<<"Found a dead end. ("<<y<<")"<<std::endl;
                                        goto next;
                                    }
                                }
                            }
                        }
                        tile=map[targetPos.y][targetPos.x];
                        switch (tile){
                            case '.':{
                                pos=targetPos;
                                visitedLocs.push_back(pos);
                            }break;
                            case '#':{
                                goto next;
                            }break;
                            case ' ':{
                                
                            }break;
                        }
                    }break;
                }
                steps--;
            }
        } else {
            if (instruction.turn==Direction::RIGHT){
                facingDir=(Direction)((facingDir+1)%4);
            } else {
                int dir = facingDir-1;
                if (dir<0){
                    dir=3;
                }
                facingDir=(Direction)dir;
            }
            std::cout<<"Turned "<<(instruction.turn==Direction::RIGHT?"RIGHT":"LEFT")<<" to face "<<facingDir<<std::endl;
        }
        next:
        instructionMarker++;
    }
    std::cout<<"Final position: "<<pos<<" Dir:"<<facingDir<<std::endl;
    std::cout<<"Sum: "<<1000*(pos.y+1)+4*(pos.x+1)+facingDir<<std::endl;

    for (int y=0;y<map.size();y++){
        for (int x=0;x<map[y].size();x++){
            for (int i=0;i<visitedLocs.size();i++){
                if (visitedLocs[i].x==x&&visitedLocs[i].y==y){
                    std::cout<<'+';
                    goto nextit;
                }
            }
            std::cout<<map[y][x];
            nextit:;
        }
        std::cout<<std::endl;
    }

	return 0;
}