feat: 最长单词

Author: sl1673495

动态规划/最长单词-面试题 17.15.js

@@ -0,0 +1,49 @@
+/**
+ * @param {string} s
+ * @param {string[]} wordDict
+ * @return {boolean}
+ */
+let wordBreak = function (s, wordDict) {
+  let n = s.length
+  if (!n) return true
+
+  let wordSet = new Set(wordDict)
+  let dp = []
+  dp[0] = true
+
+  for (let i = 0; i <= n; i++) {
+    for (let j = i; j >= 0; j--) {
+      let word = s.slice(j, i)
+      if (wordSet.has(word) && dp[j]) {
+        dp[i] = true
+        break
+      }
+    }
+  }
+
+  return !!dp[n]
+}
+/**
+ * @param {string[]} words
+ * @return {string}
+ */
+let longestWord = function (words) {
+  // 先长度降序 后字典序升序 排序
+  words.sort((a, b) => {
+    let diff = b.length - a.length
+    if (diff !== 0) {
+      return diff
+    } else {
+      return a < b ? -1 : 1
+    }
+  })
+  words = Array.from(new Set(words))
+  for (let i = 0; i < words.length; i++) {
+    let word = words[i]
+    let rest = words.slice(0, i).concat(words.slice(i + 1))
+    if (wordBreak(word, rest)) {
+      return word
+    }
+  }
+  return ""
+}