CautiousBot、Node.js（ES5）
このボットは外に出て、他のボットの土地に火をつけようとします。火の上に3ティックも座って隠します！しかし、慎重すぎることは決してないので、常に自分の土地で火を消すのに十分に近いことを確認します。
ノート：
state.json作業ディレクトリに保存されていると呼ばれる状態ファイルを使用します。これは、他のボットの初期位置に関する情報を保存し、開始された火災を非表示にする期間を決定するために使用されます。これは、ラウンドが終了したら削除する必要があります（たとえば、ボットが勝った場合）。そうしないと、ボットは次のラウンドで混乱します。（これがルールに違反するかどうか教えてください。）splitモジュールが必要です。
#!/usr/bin/env node
// imports
var fs = require("fs");
var splitmod = require("split");
// variables
var startX, startY, currentX, currentY, board = [], state = {};
var DEBUG = false;
// utility functions
function debug(){
if(DEBUG) console.log.apply(console, arguments);
}
// calculates manhattan distance which is also the number of turns it will take to get somewhere
function manhattan(x1, y1, x2, y2){
return Math.abs(x2 - x1) + Math.abs(y2 - y1);
}
// calculates chebyshev distance (mostly used for determining if a bot is within someone's plot)
function chebyshev(x1, y1, x2, y2){
return Math.max(Math.abs(x2 - x1), Math.abs(y2 - y1));
}
// gets the board character at x, y
function get(x, y){
return board[y][x];
}
function readState(){
try {
state = JSON.parse(fs.readFileSync('state.json').toString());
debug("Opened state file");
} catch(e){
// it must be the first turn
createState();
}
}
function writeState(){
fs.writeFileSync('state.json', JSON.stringify(state));
debug("Wrote state file");
}
// finds out where all the other bots are
function getBotPositions(){
var positions = [];
for(var x = 0; x < 32; x++){
for(var y = 0; y < 32; y++){
if(get(x, y) == '@' && x != currentX && y != currentY){
positions.push({x: x, y: y});
}
}
}
return positions;
}
function createState(){
debug("Creating state");
// take a loot at where other bots are to record their land locations
var botLands = getBotPositions();
state['botLands'] = botLands;
state['turn'] = 0; // which turn is it?
state['lastFireTurn'] = -999; // which turn was the last one where this bot set a fire?
}
// finds whether a plot of land (defined by its center) has fire on it
function isLandBurning(x, y){
for(var dx = -4; dx < 5; dx++){
for(var dy = -4; dy < 5; dy++){
if(get(x + dx, y + dy).match(/[1-6]/) != null) return true;
}
}
return false;
}
// finds the fire with the highest number (and therefore the one to put out first)
function findFire(x, y){
var highestNum = 0;
var fire = {x: x, y: y};
for(var dx = -4; dx < 5; dx++){
for(var dy = -4; dy < 5; dy++){
if(get(x + dx, y + dy).match(/[1-6]/) != null){
var num = parseInt(get(x + dx, y + dy));
if(num > highestNum){
highestNum = num;
fire = {x: x + dx, y: y + dy};
}
}
}
}
return fire;
}
// figures out where to go to get somewhere
function getDirection(x1, y1, x2, y2){
var direction = 'S';
var cycx = Math.abs(y2 - y1) / Math.abs(x2 - x1);
if(cycx < 1){
if(x2 > x1) direction = 'R';
if(x2 < x1) direction = 'L';
} else {
if(y2 > y1) direction = 'D';
if(y2 < y1) direction = 'U';
}
debug("Getting direction", x1, y1, x2, y2, "result", direction);
return direction;
}
// read input
var dataCycle = 0;
process.stdin.pipe(splitmod()).on('data', function(line){
switch(dataCycle){
case 0:
startX = parseInt(line);
break;
case 1:
startY = parseInt(line);
break;
case 2:
currentX = parseInt(line);
break;
case 3:
currentY = parseInt(line);
break;
default:
board.push(line);
}
dataCycle++;
}).on('end', function(){
// main bot code
readState();
state['turn']++;
debug("It is turn", state['turn']);
// get bot positions
var botPositions = getBotPositions();
var action = {type:'X', direction:'S'};
var move = 'S';
var isMyLandBurning = isLandBurning(startX, startY);
if(isMyLandBurning){ // hurry over there ASAP!
debug("Bot land is burning!");
var pos = findFire(startX, startY);
debug("Fire found at", pos);
move = getDirection(currentX, currentY, pos.x, pos.y);
// simulate the move and figure out if/where to dump the water
var newX = currentX + (move == 'R') - (move == 'L');
var newY = currentY + (move == 'D') - (move == 'U');
if(chebyshev(newX, newY, pos.x, pos.y) < 5){
// on its own land, start dropping water like a madman
debug("Dropping water");
action.type = 'P';
// if it can put out the target fire, then do that
if(manhattan(newX, newY, pos.x, pos.y) == 1) action.direction = getDirection(newX, newY, pos.x, pos.y);
// it's not in range of the target fire, so use the time to put out other fires
// if it's moving on top of a fire, put that out
else if(get(newX, newY).match(/[1-6]/) != null) action.direction = 'S';
// if there's a fire around it then put that out
else if(get(newX + 1, newY).match(/[1-6]/) != null) action.direction = 'R';
else if(get(newX - 1, newY).match(/[1-6]/) != null) action.direction = 'L';
else if(get(newX, newY + 1).match(/[1-6]/) != null) action.direction = 'D';
else if(get(newX, newY - 1).match(/[1-6]/) != null) action.direction = 'U';
else action.direction = 'S';
}
} else {
// are there any bots that could start a fire when this bot is 6+ tiles away?
var headBack = false;
for(var i = 0; i < botPositions.length; i++){
var otherBot = botPositions[i];
var dist = manhattan(otherBot.x, otherBot.y, startX, startY) - 4;
var myDist = manhattan(currentX, currentY, startX, startY);
if(dist + 6 < myDist){
headBack = true;
break;
}
}
if(headBack){ // they're probably up to no good
debug("Bots are dangerously close, heading back");
move = getDirection(currentX, currentY, startX, startY);
} else if(state['turn'] - state['lastFireTurn'] < 3) { // no bots near own plot, time to consider other options
debug("Hiding fire");
// sneakily hide the fire if one was set :)
} else { // last option is to go find land to burn
debug("Finding land to burn");
var closestX = 999, closestY = 999;
for(var i = 0; i < state.botLands.length; i++){
var otherLand = state.botLands[i];
if(!isLandBurning(otherLand.x, otherLand.y) && chebyshev(currentX, currentY, otherLand.x, otherLand.y) > 4){ // find someone to burn
// use [-3, 3] here because on the first turn, the bots could have moved before this bot had a chance to see them
// meaning that the [-3, 3] region is the only one that is guaranteed to be on their land
for(var dx = -3; dx < 4; dx++){
for(var dy = -3; dy < 4; dy++){
var type = get(otherLand.x + dx, otherLand.y + dy);
var distThere = manhattan(currentX, currentY, otherLand.x + dx, otherLand.y + dy);
var distShortest = manhattan(currentX, currentY, closestX, closestY);
// find normal land, or wet land that will dry by the time the bot gets to it
if((type == '.' || type == '@' || (type == 'W' && distThere > 1)) && distThere < distShortest){
closestX = otherLand.x + dx;
closestY = otherLand.y + dy;
}
}
}
}
}
if(closestX != 999 && closestY != 999){ // land found; go there
debug("Target acquired", closestX, closestY);
debug("Burning land");
move = getDirection(currentX, currentY, closestX, closestY);
if(move == 'S'){ // is it on the land? If so, then burn it
action.type = 'B';
action.direction = 'S';
state['lastFireTurn'] = state['turn']; // record when the fire was set
}
} else { // everyone else's land already has a fire
debug("Default action");
// default to heading back; one can never be too safe!
move = getDirection(currentX, currentY, startX, startY);
}
}
}
// save the state file
writeState();
// output the action
console.log(move + action.type + action.direction);
});