Adv2018/d15/main.js

function readAll(cb) {
    require("fs").readFile('./input', 'utf8', (err, data) => {
        var world = new World(),
            j =0;
        data.split("\n").forEach(l => {
            if (l.length) {
                var line = [];
                for (var i =0, len = l.length; i < len; ++i) {
                    var c = l.charAt(i);
                    line.push(c == '#' ? '#' : '.');
                    if ("#.".indexOf(c) == -1) {
                        var u = new Unit(c, i, j);
                        world.units.push(u);
                    }
                }
                world.area.push(line);
                ++j;
            }
        });
        cb(world);
    });
}

function World() {
    this.area = [];
    this.units = [];
    this.age = -1;
}

World.prototype.sortUnits = function() {
    this.units.sort((a, b) => (a.py == b.py ? a.px -b.px : a.py -b.py));
}

World.prototype.step = function() {
    this.sortUnits();
    this.units.forEach(u => u.hp ? u.step(this) : null);
    ++this.age;
}

World.prototype.isEmpty = function(px, py) {
    if (this.area[py][px] == '#')
        return false;
    return !this.units.some(u => u.hp && u.px == px && u.py == py);
}

World.prototype.coordExists = function(px, py) {
    return px >= 0 && py >= 0 &&
        px < this.area[0].length &&
        py < this.area.length;
}

World.prototype.isReachable = function(from, to) {
    var map = [],
        toGo = [{ pos: from, dist: 0}],
        done = {};
    if (from[0] == to[0] && from[1] == to[1])
        return { step: from, dist: 0 };
    while (toGo.length) {
        var pos = toGo[0].pos,
            dist = toGo[0].dist,
            moves = [[ 0, -1 ], [ -1, 0 ], [ 1, 0 ], [ 0, 1 ]];
        for (var i =0; i < moves.length; ++i) {
            var newCoords = [pos[0] +moves[i][0], pos[1] +moves[i][1]];
            if (this.coordExists(newCoords[0], newCoords[1])) {
                if (newCoords[0] == to[0] && newCoords[1] == to[1])
                    return { step: pos, dist: dist +1 };
                toGo.push({pos: newCoords, dist: dist +1})
            }
        }
        done[pos[0]+'x'+pos[1]] = dist;
        toGo.splice(0, 1);
        toGo = toGo.filter(c =>
            !done[c.pos[0]+'x'+c.pos[1]] &&
            this.isEmpty(c.pos[0], c.pos[1]));
        toGo.sort((a, b) => a.dist -b.dist);
    }
    return false;
}

World.prototype.print = function() {
    var w = [];

    this.sortUnits();
    this.area.forEach(l => w.push(l.slice()));
    this.units.forEach(u => u.hp ? w[u.py][u.px] = u.type : null);
    w.forEach(l => {
        var lStr = "";
        l.forEach(c => lStr += c);
        console.log(lStr);
    });
    console.log(this.units.filter(u => u.hp));
    console.log("Age: ", this.age);
    var sumHp = 0;
    this.units.forEach(u => sumHp += u.hp);
    console.log("Sum hp: ", sumHp);
    console.log("Outcome: ", sumHp *this.age);
}

World.prototype.remainingTypes = function() {
    var types = {};
    this.units.forEach(u => u.hp ? types[u.type] = true : false);
    return Object.keys(types);
}

World.prototype.hasOpponents = function() {
    return this.remainingTypes().length > 1;
}

World.prototype.run = function(stopFnc) {
    while (stopFnc(this))
        this.step();
}

function Unit(type, px, py) {
    this.type = type;
    this.px = px;
    this.py = py;
    this.hp = 200;
    this.atk = 3;
}

Unit.prototype.step = function(world) {
    this.move(world);
    this.attack(world);
}

Unit.prototype.range = function(world, except) {
    var range = [],
        moves = [[ 0, -1 ], [ -1, 0 ], [ 1, 0 ], [ 0, 1 ]];
    moves.forEach(m => {
        if (world.coordExists(this.px +m[0], this.py +m[1]) && (world.isEmpty(this.px +m[0], this.py +m[1]) || (except && (except.px == this.px +m[0] && except.py == this.py +m[1]))))
            range.push([this.px +m[0], this.py +m[1]]);
    });
    return range;
}

Unit.prototype.move = function(world) {
    var inRange = [];

    world.units.filter(u => u.hp && u.type !== this.type).forEach(t => t.range(world, this).forEach(r => inRange.push({ unit: t, pos: r })));
    var reachable = inRange.filter(r => { r.dist = world.isReachable(r.pos, [this.px, this.py]); return r.dist !== false; });
    var dest = reachable.sort((a, b) => {
        if (a.dist.dist != b.dist.dist) return a.dist.dist -b.dist.dist;
        if (a.pos[1] == b.pos[1]) return a.pos[0] -b.pos[0];
        return a.pos[1] -b.pos[1];
    })[0];
    if (dest) {
        this.px = dest.dist.step[0];
        this.py = dest.dist.step[1];
    }
}

Unit.prototype.attack = function(world) {
    var units = world.units.filter(u => u.hp && u.type !== this.type && (Math.abs(u.px -this.px) +Math.abs(u.py -this.py)) == 1);
    if (units.length) {
        units.sort((a, b) => {
            var diff = a.hp -b.hp;
            if (diff) return diff;
            diff = a.py -b.py;
            if (diff) return diff;
            return a.px -b.px;
        });
        units[0].takeDamage(this);
    }
}

Unit.prototype.takeDamage = function(from) {
    this.hp = Math.max(0, this.hp -from.atk);
}

function ex1() {
    readAll(world => {
        world.run(world => world.hasOpponents());
        world.print();
    });
}

function ex2(min, max) {
    readAll(world => {
        var stopReason = -1,
            current = Math.floor((min +max) /2);
        world.units.forEach(u => u.type === 'E' ? u.atk = current : 0);
        world.run(world => {
            if (!world.hasOpponents()) {
                stopReason = 'E';
                return false;
            }
            if (world.units.filter(u => u.hp === 0 && u.type === 'E').length) {
                stopReason = 'G';
                return false;
            }
            return true;
        });
        if (max == min || (min +1 == current && stopReason === 'E')) {
            console.log("Min atk: " +(stopReason === 'E' ? min : min +1));
            world.print();
        } else if (stopReason == 'G') {
            console.log("Atk " +current +" not enough");
            ex2(current +1, max);
        } else {
            console.log("Atk " +current +" too much");
            ex2(min, current);
        }
    });
}

ex1();
ex2(4, 300);