[BOJ 14503] 로봇청소기

출처 : https://www.acmicpc.net/problem/14503

#include <iostream>

#include <algorithm>

using namespace std;

int N, M, K, result, direction, starti, startj;

int map[50][50];

bool visited[50][50];

int dir[4][2] = { {0,-1},{1,0},{0,1},{-1,0} };

bool finished;

void cal(int i, int j, int d)

{

if (finished) return;

visited[i][j] = true; map[i][j] = 2;

int startD;

if (d == 0) startD = 0;

else if (d == 1) startD = 3;

else if (d == 2) startD = 2;

else if (d == 3) startD = 1;

int count = 0; int direc = startD;

while (count < 4)

{

if (direc == 4) direc = 0;

int nexti = i + dir[direc][0]; int nextj = j + dir[direc][1];

if (nexti>0 && nextj >0 && !visited[nexti][nextj])

{

int zz;

if (direc == 0) zz = 3;

else if (direc == 1) zz = 2;

else if (direc == 2) zz = 1;

else if (direc == 3) zz = 0;

cal(nexti, nextj, zz);

}

direc++;

count++;

}

int lastdirec;

if (d == 0) lastdirec = 1;

else if (d == 1) lastdirec = 0;

else if (d == 2) lastdirec = 3;

else if (d == 3) lastdirec = 2;

int lasti = i + dir[lastdirec][0]; int lastj = j + dir[lastdirec][1];

if (map[lasti][lastj] == 2)

{

cal(lasti, lastj, d);

}

else

{

finished = true; return;

}

}

int main()

{

cin >> N >> M; 

cin >> starti >> startj >> direction;

for (int i = 0; i < N; i++) for (int j = 0; j < M; j++)

{

cin >> map[i][j];

if (map[i][j]) visited[i][j] = true;

else visited[i][j] = false;

}

result = 0;

cal(starti, startj, direction);

for (int i = 0; i < N; i++) {

for (int j = 0; j < M; j++)

{

if (map[i][j] == 2) result += 1;

}

}

cout << result;

return 0;

}