37 lines
951 B
JavaScript
37 lines
951 B
JavaScript
// s = "3[a]2[bc]", 返回 "aaabcbc".
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// s = "3[a2[c]]", 返回 "accaccacc".
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// s = "2[abc]3[cd]ef", 返回 "abcabccdcdcdef".
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/**
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* @param {string} s
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* @return {string}
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*/
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export const decodeString = function (s) {
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const stack = []
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let multiple = ''
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for (let i = 0, len = s.length; i < len; i++) {
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if (!isNaN(Number(s[i]))) { // 判断是数字
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if (i === 0 || !isNaN(Number(s[i - 1]))) { // 如果上一位也是数字，则
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multiple += s[i]
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} else {
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multiple = s[i]
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}
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} else if (multiple && s[i] === '[') {
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stack.push(Number(multiple))
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multiple = ''
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} else if (s[i] === ']') {
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let current = stack.pop()
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let tmpStr = ''
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while (typeof current !== 'number') {
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tmpStr = current + tmpStr
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current = stack.pop()
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}
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tmpStr = tmpStr.repeat(current)
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stack.push(tmpStr)
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} else {
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stack.push(s[i])
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}
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}
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return stack.join('')
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}
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