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def move_to_dir(old, new):
"""Converts using e.g. old position (1,1) and new position (2, 1) to a direction (RIGHT)"""
if old[0] < new[0]:
return "RIGHT"
if old[1] < new[1]:
return "DOWN"
if old[0] > new[0]:
return "LEFT"
return "UP"
def get_score(starts):
Function for calculating the score given current starting positions for all bots
# create a nested dict called graph to store which bot (o) contains which
# spot (n) at which iteration (it)
graphs = {i: {} for i in range(n_players)}
# graphset just contains a copy that is being updated from the current `occupied` places
# once no changes for any bot, indicates it stops
graphset = set(x for x in occupied)
# the order in which bots are playing this turn, e.g. if our bot is player 2: (2, 3, 1, 0)
order = list(range(my_id, n_players)) + list(range(0, my_id))
it = 1
# loop until no changes
while True:
# full gets falsified when any new move is possible by any bot in a round
full = True
# keeps track of who will end up owning the spots from this turn
moves = {}
for o in order:
# on a single turn, for each bot, `starts` contains the possible starting positions
# in case of starting round, logically there is only 1 possibility
# so: for each possibility `x` of starting for bot `o`
for x in starts[o]:
# consider all the neighbouring tiles
for n in NEIGHBOURS[x]:
# if n not visitable by other bots earlier
if n not in graphset or (n in moves and it == 1):
# make sure we will continue for at least 1 more round as we found new
full = False
# add to occupied for this `get_score`
# register `neighbour` to belong to bot `o`
moves[n] = o
# update the graph with who owns in this round
for k, v in moves.items():
graphs[v][k] = it
if full:
# break since no changes were in the last round (no new possible moves)
# update the new possible starting positions for each bot
starts = [[k for k, v in moves.items() if v == i] for i in range(n_players)]
it += 1
# number of tiles we are closest to (higher=better)
num_my_tiles = len(graphs[my_id])
# number of tiles enemies are closest to (lower=better)
num_enemy_tiles = sum([len(graphs[i]) for i in range(n_players) if i != my_id])
# summed distance for reaching each tile for all enemies (higher=better)
enemies_dist = sum([sum(graphs[i].values()) for i in range(n_players) if i != my_id])
# simple weighting, importance: num_my_tiles > num_enemy_tiles > enemies_dist
return sum([num_my_tiles * 10000000, num_enemy_tiles * -100000, enemies_dist])
# NEIGHBOURS is a constant structure that gives the neighbouring tiles (e.g. 4 neighbours for a centered square)
# NEIGHBOURS[(2,2)] would give [(1,2), (2,1), (3, 2), (2, 3)]
for i in range(30):
for j in range(20):
neighbours = []
if i < 29:
neighbours.append((i + 1, j))
if i > 0:
neighbours.append((i - 1, j))
if j < 19:
neighbours.append((i, j + 1))
if j > 0:
neighbours.append((i, j - 1))
NEIGHBOURS[(i, j)] = neighbours
# `occupied` contains all the previously visited spots by bots
occupied = {}
# loop as long as the game lasts
while True:
# each turn we receive the number of players (n_players) and our id
# (my_id) from the codingame engine
n_players, my_id = [int(i) for i in input().split()]
# curr_moves will consist of the previously played move for each bot
curr_moves = []
for i in range(n_players):
# for each player, obtain the old and new coordinates
x0, y0, x1, y1 = [int(j) for j in input().split()]
occupied[(x0, y0)] = i
occupied[(x1, y1)] = i
curr_moves.append((x1, y1))
for i, cm in enumerate(curr_moves):
# (-1, -1) indicates bot is dead
if cm == (-1, -1):
occupied = {k: v for k, v in occupied.items() if v != i}
for p in range(n_players):
x1, y1 = curr_moves[p]
# currently only calculate from "our" perspective
if p == my_id:
# our current location
me = (x1, y1)
scores = []
# loop over our neighbouring tiles
for neighbour in NEIGHBOURS[me]:
# if a neighbour is not in occupied, it means it is still availbable and
# should be considered a starting position to calculate from how good of a
# move it is
if neighbour not in occupied:
# copy to prevent overwriting
player_starts = [[x] for x in curr_moves.copy()]
# fix our starting position to a candidate move
player_starts[my_id] = [neighbour]
# each player that is dead does not play (since no starting moves)
for i, cm in enumerate(curr_moves):
if cm == (-1, -1):
player_starts[i] = []
# gather score for board given starting positions
score = get_score(player_starts)
scores.append((score, neighbour))
# return the best move given the posible candidate moves
best_score_move = sorted(scores, key=lambda x: x[0], reverse=True)[0]
# print the direction we want to go to
print(move_to_dir(me, best_score_move[-1]))
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