2023年10月26日之前的作业

作业/数据结构-金健/JavaScript/第一章作业1.1.js

@@ -0,0 +1,40 @@
+const readline = require("readline");
+
+const rl = readline.createInterface(
+    process.stdin, process.stdout
+);
+let student_num = 10;
+let grades = new Array(student_num); // 类似于C/C++中数组的数据结构，空间复杂度O(n)
+
+function input(remain_times) {
+    if (remain_times <= 0) {
+        rl.close();
+        return;
+    }
+    rl.question("", (answer) => {
+        grades[student_num - remain_times] = parseFloat(answer); // 暂时不考虑输入错误
+        input(remain_times - 1);
+    });
+}
+rl.on("close", () => {
+    let sum = grades.reduce((sum, current) => {
+        return sum + current;
+    }, 0); // 时间复杂度O(n)
+    let average = sum / student_num;
+    console.log("平均分为：", average);
+});
+rl.write("输入"+student_num+"名学生的成绩，一个一行：\n");
+input(student_num);
+
+// 输入10名学生的成绩，一个一行：
+// 1
+// 2
+// 3
+// 4
+// 5
+// 6
+// 7
+// 8
+// 9
+// 10
+// 平均分为： 5.5

作业/数据结构-金健/JavaScript/第一章作业1.2.js

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+const readline = require("readline");
+
+const rl = readline.createInterface(
+    process.stdin, process.stdout
+);
+let student_num = 10;
+let grades = new Array(student_num); // 类似于C/C++中数组的数据结构，空间复杂度O(n)
+
+function input(remain_times) {
+    if (remain_times <= 0) {
+        rl.close();
+        return;
+    }
+    rl.question("", (answer) => {
+        grades[student_num - remain_times] = parseFloat(answer); // 暂时不考虑输入错误
+        input(remain_times - 1);
+    });
+}
+rl.on("close", () => {
+    let sum = grades.reduce((sum, current) => {
+        return sum + current;
+    }, 0); // 时间复杂度O(n)
+    let average = sum / student_num;
+    console.log("高于平均分的学生成绩为：", grades.filter((grade) => grade > average)); // 时间复杂度O(n)
+});
+rl.write("输入"+student_num+"名学生的成绩，一个一行：\n");
+input(student_num);
+
+// 输入10名学生的成绩，一个一行：
+// 1
+// 2
+// 3
+// 4
+// 5
+// 6
+// 7
+// 8
+// 9
+// 10
+// 高于平均分的学生成绩为： [ 6, 7, 8, 9, 10 ]

作业/数据结构-金健/JavaScript/第二章作业1.js

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+const readline = require("readline");
+const rl = readline.createInterface(process.stdin, process.stdout);
+
+class Node {
+    previous;
+    value;
+    next;
+}
+
+class LinkList {
+    head;
+    length;
+    constructor(length) {
+        // 还是需要头结点，此时head表示其中第0个结点，length必须大于0
+        this.length = length;
+        this.head = new Node();
+        // this.head.value = 1;
+        let current, previous = this.head;
+        for (let i = 1; i <= this.length; i++) {
+            current = new Node();
+            current.value = i;
+            previous.next = current;
+            current.previous = previous;
+            previous = current;
+        }
+        current.next = this.head.next;
+        this.head.next.previous = current;
+        // this.head.next = this.current; // 不能多重赋值，赋值语句会返回undefined
+        this.head.previous = current;
+    }
+    remove(node) {
+        node.previous.next = node.next;
+        node.next.previous = node.previous;
+        // delete node; // JavaScript里应该无法直接删除
+        this.length--;
+        return true;
+    }
+
+    // 找到从当前结点开始第n个结点（可以为负数），当前结点是第0个
+    // 并且再向后返回一个结点
+    get_n_after_node(node, n) {
+        let property_name = "next";
+        if (n < 0) {
+            property_name = "previous";
+            n = -n;
+        }
+        if (this.length < 3) return false;
+        for (let i = 0; i < n; i++) { // 向后走n个，例如从0开始，到3结束
+            node = node[property_name];
+        }
+        return node;
+    }
+}
+
+function main(people_num, num1) {
+    let link_list = new LinkList(people_num);
+    let current = link_list.head;
+    let temp;
+    while (true) {
+        temp = link_list.get_n_after_node(current, num1);
+        if (!temp) break;
+        current = temp;
+        link_list.remove(current);
+    }
+    // 此时current是最后一个被删掉的结点，它的next和previous都是存在的结点
+    current = current.next;
+    link_list.head.next = current;
+    for (let i = 0; i < link_list.length; i++) {
+        console.log(current.value);
+        current = current.next;
+    }
+}
+
+function input(prompt) {
+    return new Promise((resolve) => {
+        rl.question(prompt, (answer) => {
+            resolve(answer);
+        });
+    });
+}
+
+async function main_() {
+    people_num = parseInt(await input("输入人数"));
+    num1 = parseInt(await input("输入第一个数字"));
+    main(people_num, num1);
+    rl.close();
+}
+
+main_()
+
+// 输入人数41
+// 输入第一个数字3
+// 16
+// 31

作业/数据结构-金健/JavaScript/第二章作业2.js

@@ -0,0 +1,135 @@
+const readline = require("readline");
+const rl = readline.createInterface(process.stdin, process.stdout);
+
+class Node {
+    previous;
+    value;
+    next;
+}
+
+class LinkList {
+    head;
+    length;
+    constructor(length) {
+        // 还是需要头结点，此时head表示其中第0个结点，length必须大于0
+        this.length = length;
+        this.head = new Node();
+        // this.head.value = 1;
+        let current, previous = this.head;
+        for (let i = 1; i <= this.length; i++) {
+            current = new Node();
+            current.value = i;
+            previous.next = current;
+            current.previous = previous;
+            previous = current;
+        }
+        current.next = this.head.next;
+        this.head.next.previous = current;
+        // this.head.next = this.current; // 不能多重赋值，赋值语句会返回undefined
+        this.head.previous = current;
+    }
+    remove(node) {
+        node.previous.next = node.next;
+        node.next.previous = node.previous;
+        // delete node; // JavaScript里应该无法直接删除
+        this.length--;
+        return true;
+    }
+
+    // 找到从当前结点开始第n个结点（可以为负数），当前结点是第0个
+    // 并且再向后返回一个结点
+    get_n_after_node(node, n) {
+        let property_name = "next";
+        if (n < 0) {
+            property_name = "previous";
+            n = -n;
+        }
+        if (this.length < 3) return false;
+        for (let i = 0; i < n; i++) { // 向后走n个，例如从0开始，到3结束
+            node = node[property_name];
+        }
+        return node;
+    }
+}
+
+function main(people_num, num1, num2) {
+    let link_list = new LinkList(people_num);
+    let current = link_list.head;
+    let temp;
+    while (true) {
+        temp = link_list.get_n_after_node(current, num1);
+        if (!temp) break;
+        current = temp;
+        link_list.remove(current);
+        temp = link_list.get_n_after_node(current, num2);
+        if (!temp) break;
+        current = temp;
+        link_list.remove(current);
+    }
+    // 此时current是最后一个被删掉的结点，它的next和previous都是存在的结点
+    current = current.next;
+    link_list.head.next = current;
+    for (let i = 0; i < link_list.length; i++) {
+        console.log(current.value);
+        current = current.next;
+    }
+}
+
+function input(prompt) {
+    return new Promise((resolve) => {
+        rl.question(prompt, (answer) => {
+            resolve(answer);
+        });
+    });
+}
+
+function visualize(dryrun, link_list) {
+    if (dryrun) {
+        return;
+    }
+    let result = {
+        "kind": { "graph": true },
+        "nodes": [
+        ],
+        "edges": [
+        ]
+    };
+    let current = link_list.head.next;
+    for (let i = 0; i < link_list.length; i++) {
+        result.nodes.push({
+            "id": String(i),
+            "label": String(current.value)
+        });
+        current = current.next;
+        result.edges.push({
+            "from": String(i),
+            "to": String(i + 1)
+        });
+    }
+    result.edges[result.edges.length - 1].to = "0";
+    return result;
+}
+
+
+async function main_() {
+    visualize(true); // 不加这行可能它转化成Promise的时候不会放到闭包作用域里。
+    people_num = parseInt(await input("输入人数"));
+    num1 = parseInt(await input("输入第一个数字"));
+    num2 = parseInt(await input("输入第二个数字"));
+    main(people_num, num1, num2);
+    rl.close();
+}
+
+main_()
+
+// 输入人数10000
+// 输入第一个数字123
+// 输入第二个数字-654
+// 1299
+// 4114
+
+// 输入人数99999
+// 输入第一个数字-848
+// 输入第二个数字-351
+// 80178
+// 23680