var initialFloors = []; var initialLift = 0; var minFloor = 0; var _ = require("underscore"); var combinatorics = require("js-combinatorics"); var previous = []; var scenarios = [ { floors: initialFloors, lift: initialLift } ]; var input = require("fs").readFileSync("input.txt").toString().replace(/\r/g, ""); input.split("\n").filter((a)=>(a)).forEach((line)=>{ var floorNums = ["first", "second", "third", "fourth"]; var lineParts = line.match(/The ([^ ]+) floor contains (.*)./); var floorNum = floorNums.indexOf(lineParts[1]); initialFloors[floorNum] = []; var items = lineParts[2].replace("and ", ", ").split(", ").filter((a)=>(a)); items.forEach((item)=>{ if(item.indexOf("generator") != -1){ var itemParts = item.match(/a ([^ ]+) generator/); initialFloors[floorNum].push(["generator", itemParts[1]]) } else if(item.indexOf("microchip") != -1){ var itemParts = item.match(/a ([^ ]+)-compatible microchip/); initialFloors[floorNum].push(["microchip", itemParts[1]]) } }); }); function checkFloors(floors){ for(var floor of floors){ if(floor.filter((a)=>(a[0] == "generator")).length > 0){ for(var element of floor.filter((a)=>(a[0] == "microchip")).map((a)=>(a[1]))){ if(floor.filter((a)=>(a[0] == "generator")).map((a)=>(a[1])).indexOf(element) == -1){ return false; } } } } return true; } function getMinFloors(floors){ return floors.map((a)=>(Boolean(a.length))).indexOf(true); } function possibleScenarios(scenario){ var newScenarios = [[], []]; var ids = scenario.floors[scenario.lift].map((a, i)=>(i)); var arrangements = []; if(ids.length >= 1){ arrangements = arrangements.concat(combinatorics.combination(ids, 1).toArray()); } if(ids.length >= 2){ arrangements = arrangements.concat(combinatorics.combination(ids, 2).toArray()); } arrangements.forEach((arrangement)=>{ if(scenario.lift < 3){ var floors = JSON.parse(JSON.stringify(scenario.floors)); floors[scenario.lift + 1].push(floors[scenario.lift][arrangement[0]]); delete floors[scenario.lift][arrangement[0]]; if(arrangement.length == 2){ floors[scenario.lift + 1].push(floors[scenario.lift][arrangement[1]]); delete floors[scenario.lift][arrangement[1]]; } floors[scenario.lift] = floors[scenario.lift].filter((a)=>(a)); newScenarios[0].push({lift: scenario.lift + 1, floors: floors}); } if((scenario.lift > minFloor)){ var floors = JSON.parse(JSON.stringify(scenario.floors)); var generator = (arrangement.map((a)=>(floors[scenario.lift][a][0])).indexOf("generator") > -1); floors[scenario.lift - 1].push(floors[scenario.lift][arrangement[0]]); delete floors[scenario.lift][arrangement[0]]; if(arrangement.length == 2){ floors[scenario.lift - 1].push(floors[scenario.lift][arrangement[1]]); delete floors[scenario.lift][arrangement[1]]; } floors[scenario.lift] = floors[scenario.lift].filter((a)=>(a)); if(generator){ newScenarios[1].push({lift: scenario.lift - 1, floors: floors}); } else{ newScenarios[0].push({lift: scenario.lift - 1, floors: floors}); } } }); return newScenarios; } function nextSetOfScenarios(){ var newScenariosSets = [[], []]; for(var scenario of scenarios){ var possibleScenariosSet = possibleScenarios(scenario); newScenariosSets[0] = newScenariosSets[0].concat(possibleScenariosSet[0]); newScenariosSets[1] = newScenariosSets[1].concat(possibleScenariosSet[1]); } if(newScenariosSets[0].length > 0){ var newScenarios = newScenariosSets[0]; } else{ console.log("falling back"); var newScenarios = newScenariosSets[1]; } newScenarios = newScenarios.filter((scenario)=>(checkFloors(scenario.floors))); console.log("newLength", newScenarios.length); minFloor = newScenarios.map((scenario)=>(getMinFloors(scenario.floors))).reduce((a, b)=>(Math.max(a, b))) newScenarios = newScenarios.filter((scenario)=>(getMinFloors(scenario.floors) >= minFloor)); newScenarios = _.uniq(newScenarios, (scenario)=>(JSON.stringify(scenario))); newScenarios = newScenarios.filter((scenario)=>(previous.indexOf(JSON.stringify(scenario)) == -1)); newScenarios.map((scenario)=>(previous.push(JSON.stringify(scenario)))); console.log("MIN", minFloor); if(minFloor == 3){ console.log("SOLVED"); } scenarios = newScenarios; } var i = 0; while(minFloor < 3){ i++; nextSetOfScenarios(); console.log(scenarios.length); } console.log(i);