Bitburner – 從自動部屬 Hacknet 入門

在整個撰寫的過程中, 需要到處蒐集資訊 (API document/IDE 提示/別人的程式碼…etc)

hacknet 相關的 API 都集中在一起:

找到所有的 server, 就會用到 numNodes

    const count = ns.hacknet.numNodes();
    for (let i = 0; i < count; i++) { ... }

取得購買新節點的費用: getPurchaseNodeCost

  const cost = ns.hacknet.getPurchaseNodeCost();

升級相關費用的 API 參數需求都長得一樣

cost = ns.hacknet.getLevelUpgradeCost(nodeIndex, 1);

cost = ns.hacknet.getRamUpgradeCost(nodeIndex, 1);

cost = ns.hacknet.getCoreUpgradeCost(nodeIndex, 1);

JS 相關語法:

• for-loop

以上這些就可以先找出最低價的項目:

/** @param {NS} ns **/
export async function main(ns) {
    // 預設以購買新 node server 為開頭
    // 紀錄最便宜的花費
    let cheapestCost = ns.hacknet.getPurchaseNodeCost();
    // 紀錄最便宜項目的node序號(如果有的話)
    let cheapestIndex = -1;
    // 紀錄最便宜項目的類型
    let cheapestType = "new";
    // 取得目前擁有的節點數量
    const count = ns.hacknet.numNodes();
    // 遍歷所有節點
    for (let i = 0; i < count; i++) {
        // upgrade level
        let cost = ns.hacknet.getLevelUpgradeCost(i, 1);
        ns.print(`node: ${i}, cost of level: ${cost}, cheapestCost: ${cheapestCost}`);
        if (cost < cheapestCost) {
            cheapestCost = cost;
            cheapestIndex = i;
            cheapestType = "level";
        }
        // upgrade ram
        cost = ns.hacknet.getRamUpgradeCost(i, 1);
        ns.print(`node: ${i}, cost of ram: ${cost}, cheapestCost: ${cheapestCost}`);
        if (cost < cheapestCost) {
            cheapestCost = cost;
            cheapestIndex = i;
            cheapestType = "ram";
        }
        // upgrade core
        cost = ns.hacknet.getCoreUpgradeCost(i, 1);
        ns.print(`node: ${i}, cost of core: ${cost}, cheapestCost: ${cheapestCost}`);
        if (cost < cheapestCost) {
            cheapestCost = cost;
            cheapestIndex = i;
            cheapestType = "core";
        }
    }
    // show hint
    ns.print(`cheapest item is node ${cheapestIndex}'s ${cheapestType}, cost is ${cheapestCost}`);
}

這段就是像在 UI 上的檢查流程

既然找到目標, 確認 log 內容也沒問題, 就可以付諸行動

這裡會用到:

JS 相關:

• switch-case

就可以寫成:

switch (cheapestType) {
    case "new":
        ns.hacknet.purchaseNode();
        ns.print(`buy new node`);
        break;
    case "level":
        ns.hacknet.upgradeLevel(cheapestIndex, 1);
        ns.print(`upgrade ${cheapestIndex}'s level`);
        break;
    case "ram":
        ns.hacknet.upgradeRam(cheapestIndex, 1);
        ns.print(`upgrade ${cheapestIndex}'s ram`);
        break;
    case "core":
        ns.hacknet.upgradeCore(cheapestIndex, 1);
        ns.print(`upgrade ${cheapestIndex}'s core`);
        break;
}

確認上述內容都可以正確如預期般的運作

最後就是讓它在背景持續地運作

這裡會用到:

• sleep

就可以寫成:

while(true) {
  // do something here...

  // 等待 5000 毫秒(等同於 5 秒)
  await ns.sleep(5000)
}

實作-all

整個合在一起就變成:

export async function main(ns) {
    while (true) {
        // 預設以購買新 node server 為開頭
        // 紀錄最便宜的花費
        let cheapestCost = ns.hacknet.getPurchaseNodeCost();
        // 紀錄最便宜項目的node序號(如果有的話)
        let cheapestIndex = -1;
        // 紀錄最便宜項目的類型
        let cheapestType = "new";
        // 取得目前擁有的節點數量
        const count = ns.hacknet.numNodes();
        for (let i = 0; i < count; i++) {
            // upgrade level
            let cost = ns.hacknet.getLevelUpgradeCost(i, 1);
            ns.print(`node: ${i}, cost of level: ${cost}, cheapestCost: ${cheapestCost}`);
            if (cost < cheapestCost) {
                cheapestCost = cost;
                cheapestIndex = i;
                cheapestType = "level";
            }
            // upgrade ram
            cost = ns.hacknet.getRamUpgradeCost(i, 1);
            ns.print(`node: ${i}, cost of ram: ${cost}, cheapestCost: ${cheapestCost}`);
            if (cost < cheapestCost) {
                cheapestCost = cost;
                cheapestIndex = i;
                cheapestType = "ram";
            }
            // upgrade core
            cost = ns.hacknet.getCoreUpgradeCost(i, 1);
            ns.print(`node: ${i}, cost of core: ${cost}, cheapestCost: ${cheapestCost}`);
            if (cost < cheapestCost) {
                cheapestCost = cost;
                cheapestIndex = i;
                cheapestType = "core";
            }
        }
        // show hint
        ns.print(`cheapest item is node ${cheapestIndex}'s ${cheapestType}, cost is ${cheapestCost}`);
        // 確認是否有項目被找到
        if (cheapestCost < Number.MAX_VALUE) {
            switch (cheapestType) {
                case "new":
                    ns.hacknet.purchaseNode();
                    ns.print(`buy new node`);
                    break;
                case "level":
                    ns.hacknet.upgradeLevel(cheapestIndex, 1);
                    ns.print(`upgrade ${cheapestIndex}'s level`);
                    break;
                case "ram":
                    ns.hacknet.upgradeRam(cheapestIndex, 1);
                    ns.print(`upgrade ${cheapestIndex}'s ram`);
                    break;
                case "core":
                    ns.hacknet.upgradeCore(cheapestIndex, 1);
                    ns.print(`upgrade ${cheapestIndex}'s core`);
                    break;
            }
        }
        // 等待一會
        await ns.sleep(5000);
    }
}

最後…還沒結束

這是從實際操作轉成程式碼的最基本型態, 下一步就會依據此版本為基礎不但地進行改造, e.g.:

• 升級花費不超過某個價格
• 控制檢查頻率
• 強化閱讀性
• 應對一些少見的/極端的狀況
• 其他更好的演算法