Algorithms and Data Structures implemented in JavaScript for beginners, following best practices.
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/**
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* @function firstUniqChar
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* @description Given a string str, find the first non-repeating character in it and return its index. If it does not exist, return -1.
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* @param {String} str - The input string
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* @return {Number} - The index of first unique character.
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* @example firstUniqChar("javascript") => 0
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* @example firstUniqChar("sesquipedalian") => 3
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* @example firstUniqChar("aabb") => -1
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*/
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const firstUniqChar = (str) => {
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if (typeof str !== 'string') {
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throw new TypeError('Argument should be string')
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}
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const count = new Map()
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for (const char of str) {
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if (!count[char]) {
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count[char] = 1
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} else {
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count[char]++
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}
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}
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for (let i = 0; i < str.length; i++) {
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if (count[str[i]] === 1) return i
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}
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return -1
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}
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export { firstUniqChar }
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