제출 #956418

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
956418		Dan4Life	로봇 대회 (IOI23_robot)	C++17	컴파일 에러	0 ms	0 KiB

robot

#include "robot.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;


int boundary = -2, obstacle = -1, white = 0, yellow = 1, blue = 2, red = 3, green = 4;
string dir = "WSENHT";
int i, j, k, l, m;

char get_dir(int col, vector<int> subset={1,2,3,4}){
    int pos = 4;
    for(auto u : subset){
        else if(u==2 and k==col) pos=1;
        if(u==1 and j==col) pos=0;
        else if(u==4 and m==col) pos=3;
        else if(u==3 and l==col) pos=2;
    }
    return dir[pos];
}

bool exists_neighbour(int col, vector<int> subset={1,2,3,4}){
    for(auto u : subset){
        if(u==2 and k==col) return true;
        if(u==1 and j==col) return true;
        if(u==4 and m==col) return true;
        if(u==3 and l==col) return true;
    }
    return false;
}

void program_pulibot()
{
    for(i = 0; i <= 4; i++){
        for(j = -2; j <= 4; j++){
            for(k = -2; k <= 4; k++){
                for(l = -2; l <= 4; l++){
                    for(m = -2; m <= 4; m++){
                        if(k==boundary and l==boundary){
                            // final location, start coloring with yellow, go back to last blue
                            set_instruction({i,j,k,l,m},yellow,get_dir(blue));
                        }
                        else if(exists_neighbour(green)){
                            // if green somewhere, we are in the final backtrack phase
                            // in this phase, we are going to make sure we backtrack to the right path

                            if(exists_neighbour(red)){
                                set_instruction({i,j,k,l,m},green,get_dir(red));
                            }
                            else{
                                // if we are in a blocked place already, clear it, traverse back
                                set_instruction({i,j,k,l,m},white,get_dir(green));
                            }
                        }
                        else if(i==green){
                            set_instruction({i,j,k,l,m},white,get_dir(yellow));
                        }
                        else if(exists_neighbour(yellow)){
                            // if yellow somewhere, we are in the final phase
                            // in this phase, we are going to remove all the extraneous colors

                            if(exists_neighbour(red)){
                                // firstly if there's red cell, go there while marking here as yellow
                                // if i'm already on a red cell tho, paint it green
                                set_instruction({i,j,k,l,m},(i==red?green:yellow),get_dir(red));
                            }
                            else if(exists_neighbour(blue)){
                                // if no red cell, but there are blue cells, go there
                                set_instruction({i,j,k,l,m},yellow,get_dir(blue));
                            }
                            else if(j==boundary and m==boundary){
                                // starting location we can terminate now
                                set_instruction({i,j,k,l,m},yellow,'T');
                            }
                            else{
                                // if we are in a blocked place already, clear it, traverse back
                                set_instruction({i,j,k,l,m},white,get_dir(yellow));
                            }
                        }
                        else if(exists_neighbour(white,{2,3})){
                            // if still in the exploration phase and we can explore down or right:
                            // go to the next unvisited position
                            set_instruction({i,j,k,l,m},blue,get_dir(white,{2,3}));
                        }
                        else if(exists_neighbour(blue)){
                            // no where to go, mark as blocked, backtrack
                            set_instruction({i,j,k,l,m},red,get_dir(blue));
                        }
                    }
                }
            }
        }
    }
}

컴파일 시 표준 에러 (stderr) 메시지

robot.cpp: In function 'char get_dir(int, std::vector<int>)':
robot.cpp:19:9: error: 'else' without a previous 'if'
   19 |         else if(u==2 and k==col) pos=1;
      |         ^~~~