1

Author: 宋子龙

linkedList/linkedList.html

@@ -10,146 +10,148 @@
 const log = console.log
 
 class Node {
-	constructor(element) {
-		this.element = element;
-		this.next = null;
-	}
+  constructor(element) {
+    this.element = element;
+    this.next = null;
+  }
 }
 
 class LinkedList {
-	constructor() {
-		this.length = 0;
-		this.head = null;
-	}
-
-	/** 向列表尾部添加元素*/
-	append(element) {
-		const node = new Node(element);
-		let current = null;
-
-		if (!this.head) {
-			this.head = node;
-		} else {
-			current = this.head;
-
-			// 找到最末尾的元素
-			while (current.next) {
-				current = current.next;
-			}
-			current.next = node;
-		}
-
-		this.length++;
-	}
-
-	/** 向特定位置插入元素
-	 * @param {Number} position 要将元素插入链表的位置
-	 * @param {any}
-	 * @return {Boolean} 返回插入状态
-	*/
-	insert(position, element) {
-		const node = new Node(element);
-		let current = this.head,
-			previous = null;
-
-		const isValidPosition =
-			(typeof position === 'number') && (position >= 0) && (position < this.length);
-		if (!isValidPosition) { return false }
-
-		if (position === 0) {
-			node.next = current;
-			this.head = node;
-		} else {
-			for (let i = 0; i < position; i++) {
-				previous = current;
-				current = current.next;
-			}
-
-			node.next = current;
-			previous.next = node;
-		}
-		this.length++;
-		return true;
-	}
-
-	/** 移除指定元素
-	 * @return 移除成功时，返回被移除的元素
-	*/
-	remove(element) {
-		let current = this.head,
-			previous = null;
-
-		if (this.head.element === element) {
-			this.head = current.next;
-			this.length--;
-			return current.element;
-		}
-
-		while (current.next) {
-			previous = current;
-			current = current.next;
-
-			if (current.element === element) {
-				previous.next = current.next;
-				this.length--;
-				return current.element;
-			}
-		}
-
-		return null;
-	}
-
-	/** 从列表的特定位置移除一项
-	 * @return 移除成功时，返回被移除的元素
-	*/
-	removeAt(position) {
-		const isValidPosition =
-			(typeof position === 'number') && (position >= 0) && (position < this.length);
-
-		if (isValidPosition) {
-			let current = this.head,
-				previous = null;
-
-			if (position === 0) {
-				this.head = current.next;
-			} else {
-				for (let i = 0; i < position; i++) {
-					previous = current;
-					current = current.next;
-				}
-
-				// 将 current node 从链表 链中移除
-				previous.next = current.next;
-			}
-			this.length--;
-			return current.element;
-		}
-
-		if (!isValidPosition) { return null }
-	}
-
-	/** 返回元素在列表中的索引；若无改元素，返回 -1
-	 * 
-	*/
-	indexOf(element) {
-
-	}
-
-	/** 检查链表为空时，返回 true
-	 * 
-	*/
-	isEmpty() {
-
-	}
-
-	/** 返回链表元素个数 
-	 * @return {Number}
-	*/
-	size() {
-
-	}
-
-
+  constructor() {
+    this.length = 0;
+    this.head = null;
+  }
+
+  /** 向列表尾部添加元素*/
+  append(element) {
+    const node = new Node(element);
+    let current = null;
+
+    if (!this.head) {
+      this.head = node;
+    } else {
+      current = this.head;
+
+      // 找到最末尾的元素
+      while (current.next) {
+        current = current.next;
+      }
+      current.next = node;
+    }
+
+    this.length++;
+  }
+
+  /** 向特定位置插入元素
+   * @param {Number} position 要将元素插入链表的位置
+   * @param {any}
+   * @return {Boolean} 返回插入状态
+   */
+  insert(position, element) {
+    const node = new Node(element);
+    let current = this.head,
+      previous = null;
+
+    const isValidPosition =
+      (typeof position === 'number') && (position >= 0) && (position < this.length);
+    if (!isValidPosition) {
+      return false
+    }
+
+    if (position === 0) {
+      node.next = current;
+      this.head = node;
+    } else {
+      for (let i = 0; i < position; i++) {
+        previous = current;
+        current = current.next;
+      }
+
+      node.next = current;
+      previous.next = node;
+    }
+    this.length++;
+    return true;
+  }
+
+  /** 移除指定元素
+   * @return 移除成功时，返回被移除的元素
+   */
+  remove(element) {
+    let current = this.head,
+      previous = null;
+
+    if (this.head.element === element) {
+      this.head = current.next;
+      this.length--;
+      return current.element;
+    }
+
+    while (current.next) {
+      previous = current;
+      current = current.next;
+
+      if (current.element === element) {
+        previous.next = current.next;
+        this.length--;
+        return current.element;
+      }
+    }
+
+    return null;
+  }
+
+  /** 从列表的特定位置移除一项
+   * @return 移除成功时，返回被移除的元素
+   */
+  removeAt(position) {
+    const isValidPosition =
+      (typeof position === 'number') && (position >= 0) && (position < this.length);
+
+    if (isValidPosition) {
+      let current = this.head,
+        previous = null;
+
+      if (position === 0) {
+        this.head = current.next;
+      } else {
+        for (let i = 0; i < position; i++) {
+          previous = current;
+          current = current.next;
+        }
+
+        // 将 current node 从链表 链中移除
+        previous.next = current.next;
+      }
+      this.length--;
+      return current.element;
+    }
+
+    if (!isValidPosition) {
+      return null
+    }
+  }
+
+  /** 返回元素在列表中的索引；若无改元素，返回 -1
+   * 
+   */
+  indexOf(element) {
+
+  }
+
+  /** 检查链表为空时，返回 true
+   * 
+   */
+  isEmpty() {
+
+  }
+
+  /** 返回链表元素个数 
+   * @return {Number}
+   */
+  size() {
+
+  }
 
 }