js-practice/src/string/maximum-number-of-vowels-in-a-substring-of-given-length.js

46 lines
705 B
JavaScript

const v = ['a', 'e', 'i', 'o', 'u']
const check = (str) => {
const map = new Map()
for (let i = 0; i < str.length; i++) {
if (v.includes(str[i])) {
map.set(str[i], (map.get(str[i]) || 0) + 1)
}
}
let res = 0
map.forEach(n => {
res += n
})
return res
}
/**
* @param {string} s
* @param {number} k
* @return {number}
*/
export const maxVowels = function (s, k) {
let i = 0
let res = 0
const temp = s.slice(i, i + k)
let tmp = check(temp)
res = Math.max(res, tmp)
while (i + k <= s.length) {
i++
if (v.includes(s[i + k - 1])) {
tmp++
}
if (v.includes(s[i - 1])) {
tmp--
}
res = Math.max(res, tmp)
}
return res
}