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export default {} /** * HW0-1（机试） *
第一行输入一个字符串以逗号分隔，第二行输入一个目标值。找出字符串中连续字串之和等于目标值， * 符合该条件的最大字串。输出最大字串的长度。如果没有返回-1。
* eg: ‘1,2,3,4,5,6,7,1,2,4,5,6’ ‘6’ => 3 解释(1,2,3) * eg:
‘1,2,3,4,5,6,7,1,1,1,1,1,1,1,1’ ‘6’ => 6 解释(1,1,1,1,1,1) */ { const arr = [2, 3,
1, 2, 4, 3] const target = 7 const minSubArrayLen = function (target, nums) {
let left = 0, right = 0, len = -Infinity, sum = 0; while (right < nums.length) {
sum+= nums[right] while(sum >= target){ sum === target && (len = Math.max(len,
right- left + 1)) sum -= nums[left] left++ } right++ } return len === -Infinity
? -1 : len; }; // console.log('---------------HW0-1----------------'); console.
log(minSubArrayLen(target, arr)); } /** * HW0-2 *
给一段话很长的句子，第二行输入一个前缀，找出以以这个为前缀的单词并进行排序，如果没有返回-1。注意don’t看成don 和 t * eg：'Happiness
is like a pebble dropped into a pool to set in motion an ever-widening circle
of ripples As Stevenson has said, being happy is a duty ’ * 前缀：dr 输出 dropped *
(建立字典是为了后续查找) * 建立字典快，空间需要比法二少，查询效率低于法二 */ // 法一：建立字典快，空间需要比法二少，查询效率低于法二 { const
str= "adf abc aef bf ab don't" const per = 'a' const searchSuggest = (str) => {
const dict = {} const handleDict = (str, dict) => { const arr = str.split(' ')
const createDict = (word, dict) => { if (word.length === 1) { if (!dict[word]) {
// 根单词添加标识 dict[word] = { isRootWord: true } return dict } else { // 根单词添加标识
return Object.assign(dict[word], { isRootWord: true }) } } if (dict[word[0]]) {
// 给当前层继续挂载属性 createDict(word.slice(1), dict[word[0]]) } else { dict[word[0]] =
createDict(word.slice(1), {}) } return dict } //
因为涉及到某些单词可能是词根单词，所以需要把长度大的放在前面，这样后续处理词根单词会方便一点 arr.forEach(word => { if (word.
includes("'")) { word.split("'").forEach(w => { createDict(w, dict) }) } else {
createDict(word, dict) } }) } const searchWordInDict = (per, dict) => { // 找出前缀树
const findPerTree = (per, dict) => { if (per.length === 1) { return dict[per] }
if (dict[per[0]]) { return findPerTree(per.slice(1), dict[per[0]]) } } const
joinStr = (per, obj) => { const rstArr = [] for (let key in obj) { //
如果key是根单词说明要拼接 if (key === 'isRootWord') { rstArr.push(`${per}`) } else { rstArr
.push(...joinStr(`${per}${key}`, obj[key])) } } return rstArr } const obj =
findPerTree(per, dict) let strArr = [] // 遍历树形成word if (obj) { strArr = joinStr(
per, obj) } // 排序 const sortFun = (a, b) => { if (!a) return -1 if (!b) return 1
if (a.charCodeAt() === b.charCodeAt()) { return sortFun(a.slice(1), b.slice(1))
} return a.charCodeAt() - b.charCodeAt() } strArr.sort(sortFun) return strArr.
length> 0 ? strArr : -1 } handleDict(str, dict) return function (per = '') {
return searchWordInDict(per, dict) } } console.log(
'---------------HW0-2----------------'); console.log(searchSuggest(str)(per));
//建立字典慢，空间占用大，当单词达到100万，会卡住。 const searchSuggestion = (sentence) => { const
keywords= sentence.split(' ') const letterMap = new Map() const buildDictionary
= (keyword, parentMap = new Map(), index = 0) => { let letterGroup = keyword[
index] let letterGroupSuggestion = parentMap.get(letterGroup) // 当前字母组合有无推荐列表 if
(!letterGroupSuggestion) { letterGroupSuggestion = { suggestionList: [keyword] }
} else { const suggestionList = letterGroupSuggestion.suggestionList !
suggestionList.includes(keyword) && suggestionList.push(keyword) } //
后续还有字母,递归建立字典 if ((index < keyword.length - 1)) { const childMap =
letterGroupSuggestion.childMap || new Map() letterGroupSuggestion.childMap =
childMapbuildDictionary(keyword, childMap, index + 1) } parentMap.set(
letterGroup, letterGroupSuggestion) } keywords.forEach(keyword => {
buildDictionary(keyword, letterMap) }) return function (letterGroup = '') {
const getSuggestionList = (letterGroup, parentMap, index = 0) => { const
letterSuggestion= parentMap.get(letterGroup[index]) if (!letterSuggestion)
return -1 if (index === letterGroup.length - 1) return letterSuggestion.
suggestionListreturn getSuggestionList(letterGroup, letterSuggestion.childMap,
index+ 1) } return getSuggestionList(letterGroup, letterMap) } } console.log(
searchSuggestion(str)(per)) } /** * HW0-3 * 第一行输入一串字符串，请计算结果。其中sub( a b) 表示 a-b
, add(a b) 表示 a + b ， mult(a b)表示 a * b, div(a b)表示 a / b 。 * 如果被除数是0，则输出error
eg: * add(3 div(4 0)) => error * add(3 mult(2 6)) => 15.0 * add(1 div(1 2)) =>
1.5 */ { const str = '(add 3 (sub 4 1))' const handlekh = str => { let rst = ''
const len = str.length for (let i = 0; i < len; i++) { if (str[i] === '(') { rst
+= '( ' } else if (str[i] === ')') { rst += ' )' } else { rst += str[i] } }
return rst } const arr = handlekh(str).split(' ') const stack = [] const getRst
= (f, left, right) => { left = Number(left) right = Number(right) if (f ===
'add') return left + right if (f === 'sub') return left - right if (f === 'div')
{ if (right === 0) { return false } return Math.floor(left / right) } if (f ===
'mul') return left * right } arr.forEach(item => { if (item[0] !== ')') { stack.
push(item) } else { const right = stack.pop() const left = stack.pop() const f =
stack.pop() // 把'（'移出去 stack.pop() const rst = getRst(f, left, right) if (rst
=== false) { return console.log('error') } stack.push(rst) } }) console.log(
'---------------HW0-3----------------'); console.log(stack[0]); } /** * HW1-1 *
有效的括号，给定一个字符串只包含(){}[]，请判断是否为有效字符串 * eg:[] => true * [{] => false */ { /** *
是否匹配 * @param {string} left * @param {string} right * @returns {boolean} */
const isMatching = (left, right) => { if (left === '(' && right === ')') return
true if (left === '{' && right === '}') return true if (left === '[' && right
=== ']') return true return false } /** * @param {string} str * @returns
{boolean} */ const bracket = str => { const len = str.length if (len % 2) return
false const stank = [] const leftBracket = '([{' const rightBracket = ')]}' let
index= 0 while (index < str.length) { if (leftBracket.includes(str[index])) {
stank.push(str[index]) } else { if (!isMatching(stank.pop(), str[index])) {
return false } } index++ } return stank.length === 0 } console.log(
'---------------HW1-1----------------'); console.log(bracket('[{]')); console.
log(bracket('[]')); console.log(bracket('[{()}]')); console.log(bracket('[{(})]'
)); } /** * HW1-2 * 找出连续最长非重复字序列的长度 * eg:abcabcat => 4 * abcabcefabc => 5 */ {
/** * @param {string} str * @returns {string} */ const longestSubsequence = str
=> { const len = str.length let left = 0 let right = 0 let maxCount = 0 let map
= new Map() while(right < len){ if(map.get(str[right])){ // 证明存在,移动左指针 map.
delete(str[left]) left++ }else{ map.set(str[right],1) right++ } maxCount = Math.
max(maxCount,right-left) } return maxCount } console.log(
'---------------HW1-2----------------'); console.log(longestSubsequence(
"abcabcat")); console.log(longestSubsequence("abcaceaaaa")); console.log(
longestSubsequence("abcabcefabc")); } /** * HW2-1 *
输入一个数字，转换为二进制字符串，统计其连续相同的元素的最多个数。 * eg:3 => 11 => 2 * eg:1 => 1 => 1 * eg:0 =>
0 => 1 * eg:7 => 111 => 3 * eg:17 => 10001 => 3 */ { /** * @param {number} num
* @returns {number} */ const maximum = num => { const numStr = num.toString(2)
let count = 0 let left = 0 let right = 0 const len = numStr.length while (left <
len&& right < len) { if (numStr[left] === numStr[right]) { count = Math.max(
count, right - left + 1) } else { left = right } right++ } return count }
console.log('---------------HW2-1----------------'); console.log(maximum(1));
console.log(maximum(0)); console.log(maximum(7)); console.log(maximum(3));
console.log(maximum(17)); console.log(maximum(99)); } /** * HW2-2 *
输入英文求中文输入中文求英文，英文可包含Double。 * 英文：One Two Three Four Five Six Seven Eight Nine
Zero Double * 中文： * 如果出现DoubleDouble，则表示不合法输出ERROR，输入其余不符合的同样认为是不合法。 *
eg:YiErSanSan => OneTwoThreeThree * eg:OneTwoDoubleThree => YiErSanSan *
eg:OneTwoDoubleDoubleThree => ERROR * eg:OneTwoDoubleYiThree => ERROR *
eg:YiErDoubleSanSan => ERROR * eg:OneTwoThreeDouble => ERROR */ { /** * @param
{string} str * @returns {string} */ const chEnTranslate = str => { const ch =
"Yi Er San Si Wu Liu Qi Ba Jiu Ling".split(' ') const en = "One Two Three Four
Five Six Seven Eight Nine Zero".split(' ') const enMap = new Map() const chMap =
new Map() // 建立映射关系 ch.forEach((key, index) => { chMap.set(key, en[index]) enMap
.set(en[index], key) }) const CAPITAL = 97 // 最后增加一个结束标志 str += 'E' const len =
str.length let left = 0 let right = 1 let rst = '' let isEn = false let
doubleNum= 0 while (left < len && right < len) { if (str[right].charCodeAt() <
CAPITAL) { // 大写字母出现 const cur = str.slice(left, right) // Double不能放最后 if (right
=== (len - 1) && cur === 'Double') return 'ERROR' // 判断是中文还是英文，英文可以有'Double' if
(!rst && (en.includes(cur) || cur === 'Double')) { isEn = true } if (!isEn) {
// 中文 if (!chMap.has(cur)) return 'ERROR' rst += chMap.get(cur) } else { // 英文
if (!enMap.has(cur) && cur !== 'Double') return 'ERROR' // 处理Double if (
doubleNum) { if (cur === 'Double') return 'ERROR' rst += (enMap.get(cur) + enMap
.get(cur)) doubleNum = 0 //重置doubleNum } else if (cur !== 'Double') { rst +=
enMap.get(cur) } else { doubleNum = 1 } } left = right } right++ } return rst }
console.log('---------------HW2-2----------------'); console.log(chEnTranslate(
'YiErSanSan')); console.log(chEnTranslate('OneTwoDoubleThree')); console.log(
chEnTranslate('OneTwoDoubleDoubleThree')); console.log(chEnTranslate(
'OneTwoDoubleYiThree')); console.log(chEnTranslate('YiErDoubleSanSan')); console
.log(chEnTranslate('OneTwoThreeDouble')); console.log(chEnTranslate(
'DoubleOneTwoThree')); console.log(chEnTranslate(
'DoubleOneDoubleTwoDoubleThreeDoubleSix')); console.log(chEnTranslate(
'SiSiSiErSan')); } // HW3-1 //
给定N个队伍，每次选两个最高的队伍出来比赛，如果人数相等则消亡两个队伍，否则将两队比赛的结果产生的新队伍放入总队伍中， // 依次这样比赛，求最后比赛结果。 {
/** * @param {number[]} arr * @returns {number[]} */ const match = arr => { if(
arr.length < 2) return arr arr.sort((x,y)=>y-x) const rst = arr[0] - arr[1] //
此处可以考虑上面已经做了排序，只需要把新的数据插入到数组中合适的位置， // 那么递归就不需要从match开始，在内部实现后续的arr[1]和arr[0]的比较
if(rst === 0) return match(arr.slice(2)) return match(arr.slice(2).concat(rst))
} console.log(match([1,2,3,4,5,1])); }