https://leetcode.cn/problems/word-ladder/

Author: masx200

README.md

@@ -10,6 +10,8 @@ leetcode 测试
 
 ##### 包含的内容如下
 
+https://leetcode.cn/problems/word-ladder/
+
 https://leetcode.cn/problems/add-one-row-to-tree/
 
 https://leetcode.cn/problems/minimum-subsequence-in-non-increasing-order/

add-one-row-to-tree/test.ts

@@ -0,0 +1,84 @@
+import { assertEquals } from "../deps.ts";
+import { TreeNode } from "../mod.ts";
+import addOneRow from "./index.ts";
+
+Deno.test("add-one-row-to-tree", () => {
+    const outputs = [
+        {
+            val: 4,
+            left: {
+                val: 1,
+                left: {
+                    val: 2,
+                    left: { val: 3, left: null, right: null },
+                    right: { val: 1, left: null, right: null },
+                },
+                right: null,
+            },
+            right: {
+                val: 1,
+                left: null,
+                right: {
+                    val: 6,
+                    left: { val: 5, left: null, right: null },
+                    right: null,
+                },
+            },
+        },
+        {
+            val: 4,
+            left: {
+                val: 2,
+                left: {
+                    val: 1,
+                    left: { val: 3, left: null, right: null },
+                    right: null,
+                },
+                right: {
+                    val: 1,
+                    left: null,
+                    right: { val: 1, left: null, right: null },
+                },
+            },
+            right: null,
+        },
+    ];
+    const inputs = [
+        [
+            {
+                val: 4,
+                left: {
+                    val: 2,
+                    left: { val: 3, left: null, right: null },
+                    right: { val: 1, left: null, right: null },
+                },
+                right: {
+                    val: 6,
+                    left: { val: 5, left: null, right: null },
+                    right: null,
+                },
+            },
+            1,
+            2,
+        ],
+        [
+            {
+                val: 4,
+                left: {
+                    val: 2,
+                    left: { val: 3, left: null, right: null },
+                    right: { val: 1, left: null, right: null },
+                },
+                right: null,
+            },
+            1,
+            3,
+        ],
+    ] as Array<[root: TreeNode | null, val: number, depth: number]>;
+    assertEquals(
+        outputs,
+        inputs.map((args) =>
+            structuredClone(Reflect.apply(addOneRow, null, args))
+        ),
+    );
+});

word-ladder/index.ts

@@ -0,0 +1,52 @@
+export default function ladderLength(
+    beginWord: string,
+    endWord: string,
+    wordList: string[],
+): number {
+    const words = new Set(wordList);
+    if (!words.has(endWord)) return 0;
+
+    if (beginWord.length === 1) return 2;
+
+    let current = new Set([beginWord]);
+
+    let rightcurrent = new Set([endWord]);
+    words.delete(endWord);
+    let step = 1;
+    while (current.size) {
+        if (current.size > rightcurrent.size) {
+            [current, rightcurrent] = [rightcurrent, current];
+        }
+
+        const temp: Set<string> = new Set();
+
+        for (const word of current) {
+            for (const right of rightcurrent) {
+                if (diffonechar(word, right)) {
+                    return step + 1;
+                }
+            }
+            for (const other of words) {
+                if (diffonechar(other, word)) {
+                    temp.add(other);
+
+                    words.delete(other);
+                }
+            }
+        }
+
+        if (temp.size === 0) return 0;
+        current = temp;
+        step = step + 1;
+    }
+
+    return 0;
+}
+
+function diffonechar(word1: string, word2: string): boolean {
+    let changes = 0;
+    for (let i = 0; i < word1.length; i++) {
+        if (word1[i] != word2[i]) changes += 1;
+    }
+    return changes === 1;
+}

word-ladder/test.ts

@@ -0,0 +1,21 @@
+import { assertEquals } from "https://deno.land/[email protected]/testing/asserts.ts";
+import ladderLength from "./index.ts";
+
+Deno.test("word-ladder", () => {
+    const beginWord = "hit",
+        endWord = "cog",
+        wordList = ["hot", "dot", "dog", "lot", "log", "cog"];
+    assertEquals(5, ladderLength(beginWord, endWord, wordList));
+});
+Deno.test("word-ladder", () => {
+    const beginWord = "hit",
+        endWord = "cog",
+        wordList = ["hot", "dot", "dog", "lot", "log"];
+    assertEquals(0, ladderLength(beginWord, endWord, wordList));
+});
+Deno.test("word-ladder", () => {
+    assertEquals(2, ladderLength("a", "c", ["a", "b", "c"]));
+});
+Deno.test("word-ladder", () => {
+    assertEquals(0, ladderLength("hot", "dog", ["hot", "dog"]));
+});