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758. Bold Words in String
Description
Given an array of keywords words and a string s, make all appearances of all keywords words[i] in s bold. Any letters between <b> and </b> tags become bold.
Return s after adding the bold tags. The returned string should use the least number of tags possible, and the tags should form a valid combination.
Example 1:
Input: words = ["ab","bc"], s = "aabcd"
Output: "a<b>abc</b>d"
Explanation: Note that returning "a<b>a<b>b</b>c</b>d" would use more tags, so it is incorrect.
Example 2:
Input: words = ["ab","cb"], s = "aabcd" Output: "a<b>ab</b>cd"
Constraints:
1 <= s.length <= 5000 <= words.length <= 501 <= words[i].length <= 10sandwords[i]consist of lowercase English letters.
Note: This question is the same as 616: https://leetcode.com/problems/add-bold-tag-in-string/
Solutions
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class Trie { Trie[] children = new Trie[128]; boolean isEnd; public void insert(String word) { Trie node = this; for (char c : word.toCharArray()) { if (node.children[c] == null) { node.children[c] = new Trie(); } node = node.children[c]; } node.isEnd = true; } } class Solution { public String boldWords(String[] words, String s) { Trie trie = new Trie(); for (String w : words) { trie.insert(w); } List<int[]> pairs = new ArrayList<>(); int n = s.length(); for (int i = 0; i < n; ++i) { Trie node = trie; for (int j = i; j < n; ++j) { int idx = s.charAt(j); if (node.children[idx] == null) { break; } node = node.children[idx]; if (node.isEnd) { pairs.add(new int[] {i, j}); } } } if (pairs.isEmpty()) { return s; } List<int[]> t = new ArrayList<>(); int st = pairs.get(0)[0], ed = pairs.get(0)[1]; for (int j = 1; j < pairs.size(); ++j) { int a = pairs.get(j)[0], b = pairs.get(j)[1]; if (ed + 1 < a) { t.add(new int[] {st, ed}); st = a; ed = b; } else { ed = Math.max(ed, b); } } t.add(new int[] {st, ed}); int i = 0, j = 0; StringBuilder ans = new StringBuilder(); while (i < n) { if (j == t.size()) { ans.append(s.substring(i)); break; } st = t.get(j)[0]; ed = t.get(j)[1]; if (i < st) { ans.append(s.substring(i, st)); } ++j; ans.append("<b>"); ans.append(s.substring(st, ed + 1)); ans.append("</b>"); i = ed + 1; } return ans.toString(); } } -
class Trie { public: vector<Trie*> children; bool isEnd; Trie() { children.resize(128); isEnd = false; } void insert(string word) { Trie* node = this; for (char c : word) { if (!node->children[c]) node->children[c] = new Trie(); node = node->children[c]; } node->isEnd = true; } }; class Solution { public: string boldWords(vector<string>& words, string s) { Trie* trie = new Trie(); for (string w : words) trie->insert(w); int n = s.size(); vector<pair<int, int>> pairs; for (int i = 0; i < n; ++i) { Trie* node = trie; for (int j = i; j < n; ++j) { int idx = s[j]; if (!node->children[idx]) break; node = node->children[idx]; if (node->isEnd) pairs.push_back({i, j}); } } if (pairs.empty()) return s; vector<pair<int, int>> t; int st = pairs[0].first, ed = pairs[0].second; for (int i = 1; i < pairs.size(); ++i) { int a = pairs[i].first, b = pairs[i].second; if (ed + 1 < a) { t.push_back({st, ed}); st = a, ed = b; } else ed = max(ed, b); } t.push_back({st, ed}); string ans = ""; int i = 0, j = 0; while (i < n) { if (j == t.size()) { ans += s.substr(i); break; } st = t[j].first, ed = t[j].second; if (i < st) ans += s.substr(i, st - i); ans += "<b>"; ans += s.substr(st, ed - st + 1); ans += "</b>"; i = ed + 1; ++j; } return ans; } }; -
class Trie: def __init__(self): self.children = [None] * 128 self.is_end = False def insert(self, word): node = self for c in word: idx = ord(c) if node.children[idx] is None: node.children[idx] = Trie() node = node.children[idx] node.is_end = True class Solution: def boldWords(self, words: List[str], s: str) -> str: trie = Trie() for w in words: trie.insert(w) n = len(s) pairs = [] for i in range(n): node = trie for j in range(i, n): idx = ord(s[j]) if node.children[idx] is None: break node = node.children[idx] if node.is_end: pairs.append([i, j]) if not pairs: return s st, ed = pairs[0] t = [] for a, b in pairs[1:]: if ed + 1 < a: t.append([st, ed]) st, ed = a, b else: ed = max(ed, b) t.append([st, ed]) ans = [] i = j = 0 while i < n: if j == len(t): ans.append(s[i:]) break st, ed = t[j] if i < st: ans.append(s[i:st]) ans.append('<b>') ans.append(s[st : ed + 1]) ans.append('</b>') j += 1 i = ed + 1 return ''.join(ans) -
type Trie struct { children [128]*Trie isEnd bool } func newTrie() *Trie { return &Trie{} } func (this *Trie) insert(word string) { node := this for _, c := range word { if node.children[c] == nil { node.children[c] = newTrie() } node = node.children[c] } node.isEnd = true } func boldWords(words []string, s string) string { trie := newTrie() for _, w := range words { trie.insert(w) } n := len(s) var pairs [][]int for i := range s { node := trie for j := i; j < n; j++ { if node.children[s[j]] == nil { break } node = node.children[s[j]] if node.isEnd { pairs = append(pairs, []int{i, j}) } } } if len(pairs) == 0 { return s } var t [][]int st, ed := pairs[0][0], pairs[0][1] for i := 1; i < len(pairs); i++ { a, b := pairs[i][0], pairs[i][1] if ed+1 < a { t = append(t, []int{st, ed}) st, ed = a, b } else { ed = max(ed, b) } } t = append(t, []int{st, ed}) var ans strings.Builder i, j := 0, 0 for i < n { if j == len(t) { ans.WriteString(s[i:]) break } st, ed = t[j][0], t[j][1] if i < st { ans.WriteString(s[i:st]) } ans.WriteString("<b>") ans.WriteString(s[st : ed+1]) ans.WriteString("</b>") i = ed + 1 j++ } return ans.String() }