Baekjoon-23291-어항 정리

N,K = map(int,input().split())
pots = list(map(int,input().split()))

debug = False

# spiral
width = 1
height = 1
remain = N-1
while remain >= height:
    remain -= height
    if width == height:
        height += 1
    else:
        width += 1

board1 = [[0]*width for _ in range(height)]
dirs = [[-1,0],[0,1],[1,0],[0,-1]]

turns = 0
while True:
    # 최소에 1 추가
    min_fish = min(pots)
    for i in range(len(pots)):
        if pots[i] == min_fish:
            pots[i] += 1

    # 첫 번째 배열
    board1 = [[0]*height for _ in range(width)]
    x,y = width-1,0
    head = 0
    for fish in reversed(pots[:N-remain]):
        board1[x][y] = fish
        dx,dy = dirs[head]
        if not (0<=x+dx<width and 0<=y+dy<height) or board1[x+dx][y+dy]!=0:
            head = (head+1)%4
            dx,dy = dirs[head]
        x,y = x+dx, y+dy

    if debug:
        print('board1')
        print(*board1, sep='\n')
        
    # 첫 번째 정리
    new_board1 = [[0]*height for _ in range(width)]
    new_remain1 = [0]*(remain+1)
    for i in range(width):
        for j in range(height):
            dir_list = []
            if i!=width-1:
                dir_list.append([1,0])
            if j!=height-1:
                dir_list.append([0,1])
            for di,dj in dir_list:
                d = board1[i][j]-board1[i+di][j+dj]
                d = abs(d)//5 if d>=0 else -(abs(d)//5)
                new_board1[i][j] -= d
                new_board1[i+di][j+dj] += d
    for i in range(remain):
        d = pots[-remain-1+i]-pots[-remain+i]
        d = abs(d)//5 if d>=0 else -(abs(d)//5)
        new_remain1[i] -= d
        new_remain1[i+1] += d
    
    if debug:
        print('board1 - after')
        print(*board1, sep='\n')
    
    # 숫자 정리
    for i in range(width):
        for j in range(height):
            board1[i][j] += new_board1[i][j]
            pots[i*height+j] = board1[i][j]
    board1[-1][0] += new_remain1[0]
    pots[(width-1)*height] = board1[-1][0]
    for i in range(remain):
        pots[i-remain] += new_remain1[i+1]

    if debug:
        print("first", pots)
    
    # 두 번째 배열
    board2 = [[0]*(N//4) for _ in range(4)]
    board2[0] = pots[N//2+N//4-1:N//2-1:-1]
    board2[1] = pots[N//4:N//2]
    board2[2] = pots[N//4-1::-1]
    board2[3] = pots[N//2+N//4:]

    # 두 번째 정리
    new_board2 = [[0]*(N//4) for _ in range(4)]
    for i in range(4):
        for j in range(N//4):
            dir_list = []
            if i!=3:
                dir_list.append([1,0])
            if j!=N//4-1:
                dir_list.append([0,1])
            for di,dj in dir_list:
                d = board2[i][j]-board2[i+di][j+dj]
                d = abs(d)//5 if d>=0 else -(abs(d)//5)
                new_board2[i][j] -= d
                new_board2[i+di][j+dj] += d
    
    # 숫자 정리
    for i in range(4):
        for j in range(N//4):
            pots[4*j+(3-i)] = board2[i][j] + new_board2[i][j]

    if debug:
        print("second", pots)
    
    turns += 1
    if max(pots) - min(pots) <= K:
        print(turns)
        exit()