Robotti

def walk_left(b, c_idx, n)
  while c_idx >= 0
    c_idx -= 1
    if b[c_idx] == "*"
      return c_idx
    end
  end
  return -1
end

def walk_right(b, c_idx, n)
  while c_idx < n && c_idx != -1
    c_idx += 1
    if b[c_idx] == "*"
      return c_idx
    end
  end
  return -1
end

board_size = gets.chomp.to_i
board = gets.chomp.split("")

steps = 0
robot_idx = board.find_index("R")
left_idx = walk_left(board, robot_idx, board_size)
right_idx = walk_right(board, robot_idx, board_size)

finished = false
coins_collected = 0

while ((2 * robot_idx - left_idx - right_idx != 0) || left_idx == -1 || right_idx == -1) && !(left_idx == -1 && right_idx == -1)
  if right_idx != -1 && (robot_idx - left_idx > right_idx - robot_idx)
    # go right
    steps += (right_idx - robot_idx).abs
    robot_idx = right_idx
    right_idx = walk_right(board, right_idx, board_size)
  elsif left_idx != -1 # unnecessary elsif, could be else but clearer this way
    # go left
    steps += (robot_idx - left_idx).abs
    robot_idx = left_idx
    left_idx = walk_left(board, left_idx, board_size)
  end
  coins_collected += 1
end

puts("#{steps} #{coins_collected}")

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 1, 2

Verdict: ACCEPTED

Test 7

Group: 1, 2

Verdict: ACCEPTED

Test 8

Group: 1, 2

Verdict: ACCEPTED

Test 9

Group: 1, 2

Verdict: ACCEPTED

Test 10

Group: 1, 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 1, 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 2

Verdict: ACCEPTED

Test 17

Group: 2

Verdict: ACCEPTED

Test 18

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 2

Verdict: ACCEPTED

Test 20

Group: 2

Verdict: ACCEPTED

Test 21

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 22

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 23

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 24

Group: 2

Verdict: ACCEPTED