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#616 - Add Bold Tag in String
Problem Description
You are given a string s and an array of strings words.
You should add a closed pair of bold tag <b> and </b> to wrap the substrings in s that exist in words.
- If two such substrings overlap, you should wrap them together with only one pair of closed bold-tag.
- If two substrings wrapped by bold tags are consecutive, you should combine them.
Return s after adding the bold tags.
Solution
/**
* @param {string} s
* @param {string[]} words
* @return {string}
*/
var addBoldTag = function(s, words) {
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;
};