[백준 문제풀이] 얼렁뚱땅 3190 뱀 풀이

https://www.acmicpc.net/problem/3190

3190번: 뱀

 

from collections import deque

def turn_dir(current, what) :
    east = [0, 2, 1, 3]
    west = [0, 3, 1, 2]

    if what == 'L' :
        idx = west.index(current)
        if idx + 1 == 4 :
            return west[0]
        else :
            return west[idx + 1]
    else :
        idx = east.index(current)
        if idx + 1 == 4 :
            return east[0]
        else :
            return east[idx + 1]


n = int(input())
apple_num = int(input())
arr = [[0]*n for _ in range(n)]
for i in range(apple_num) :
    x, y = map(int,input().split())
    arr[x-1][y-1] = 1

dir = int(input())
direction = [0] * 10001
#1초가 의미하는 숫자 0
for i in range(dir) :
    a, b= input().split()
    direction[int(a)] = b

# 동 서 남 북
dx = [0, 0, 1, -1]
dy = [1, -1, 0, 0]

current_d = 0
q = deque([[0,0]])
arr[0][0] = -1
# -1 : 지금 뱀 꿈틀
time = 1
x , y = 0, 0
while True :
    nx = x + dx[current_d]
    ny = y + dy[current_d]
    # 벽에 부딪히는지 보고, 자기 몸에 부딪히는지 봐야함
    if 0<=nx<n and 0<=ny<n and arr[nx][ny]!=-1:
        # 일단 몸 늘려
        q.append([nx,ny])
        #사과 있다 -> 사과 먹어
        if arr[nx][ny] :
            arr[nx][ny] = -1
        #사과 없다 -> 꼬리 땡겨
        else :
            arr[nx][ny] = -1
            re_x, re_y = q.popleft()
            arr[re_x][re_y] = 0
        
        x, y = nx, ny
        
        if direction[time] != 0 :
            current_d = turn_dir(current_d,direction[time])
        time += 1
    else :
        break
print(time)