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#758 - Bold Words in String
Problem 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.
Solution
/**
* @param {string[]} words
* @param {string} s
* @return {string}
*/
var boldWords = function(words, s) {
const boldIntervals = [];
for (const word of words) {
let start = s.indexOf(word);
while (start !== -1) {
boldIntervals.push([start, start + word.length]);
start = s.indexOf(word, start + 1);
}
}
if (!boldIntervals.length) return s;
boldIntervals.sort((a, b) => a[0] - b[0] || a[1] - b[1]);
const mergedIntervals = [];
let [currentStart, currentEnd] = boldIntervals[0];
for (let i = 1; i < boldIntervals.length; i++) {
const [nextStart, nextEnd] = boldIntervals[i];
if (nextStart <= currentEnd) {
currentEnd = Math.max(currentEnd, nextEnd);
} else {
mergedIntervals.push([currentStart, currentEnd]);
[currentStart, currentEnd] = [nextStart, nextEnd];
}
}
mergedIntervals.push([currentStart, currentEnd]);
let result = '';
let lastEnd = 0;
for (const [start, end] of mergedIntervals) {
result += s.slice(lastEnd, start) + '<b>' + s.slice(start, end) + '</b>';
lastEnd = end;
}
result += s.slice(lastEnd);
return result;
};