Define “Straight” as 5 cards with consecutive numbers. Determine if the deck can be fully divided into sets of “Straight”. Example: 1, 2, 3, 4, 4, 5, 5, 6, 7, 8 -> TrueYou may assume the cards are sorted 这个是用一个hashtable,key是数字,value是出现次数 然后遍历原数组,每一个数…

求两个sorted数组的intersection e.g. [1,2,3,4,5],[2,4,6] 结果是[2,4] difference 类似merge, 分小于等于大于三种情况,然后时间O(m+n), 空间O(1) package ShortestSubsequenceIncluding; import java.util.*; public class Solution2 { public ArrayList<Integer> setInters(int[] arr1, int[] ar…

字符串重新排列,让里面不能有相同字母在一起.比如aaabbb非法的,要让它变成ababab.给一种即可 Greedy: 跟FB面经Prepare task Schedule II很像,记录每个char出现次数,然后用最大堆,把剩下char里面出现次数多的优先Poll出来组建新的string 如果poll出来的char跟上一个相同,则用一个queue暂时存一下 我觉得时间复杂度:O(N) + O(KlogK) + O(NlogK) = O(NlogK) ,where K is the number…

Define “X-Straight” as X cards with consecutive numbers (X >= 3). Determine if the deck can be fully divided into sets of “X-Straight”. Example: 1, 2, 3, 4, 4, 5, 6 -> True Backtracking: package Straight; import java.util.*; public class Solution2 {…

求string str1中含有string str2 order的 subsequence 的最小长度 DP做法:dp[i][j]定义为pattern对应到i位置,string对应到j位置时,shortest substring的长度,Int_Max表示不存在 package ShortestSubsequenceIncluding; public class Solution { public String findShortest(String a, String b){ if(a==nul…

设定一个pattern 把 'internationalization' 变成 'i18n', 比如word是house,pattern可以是h3e, 3se, 5, 1o1s1等, 给pattern和word,判断是否match, package DataStreamAverage; public class Solution3 { public boolean check(String s1, String s2) { return helper(s1, 0, s2, 0); } publi…

给一个datastream和一个fixed window size, 让我design一个class可以完成add number还有find average in the window. 就是不能用vector得用array. 当然用queue是最好的 package DataStreamAverage; import java.util.*; public class Solution { int count; int sum; Queue<Integer> q; public Soluti…

1 2 3 4 5 6 7 8 9 只有中间没有其他键的两个键才能相连,比如1可以连 2 4 5 6 8 但不能连 3 7 9 但是如果中间键被使用了,那就可以连,比如5已经被使用了,那1就可以连9 每个键只能用一次,给定一个长度L,求问有多少unique path with length L Backtracking: 我的code不光可以知道数目,还可以打印所有Pattern package AndroidUnlockPattern; import java.util.*; public c…

第二题 算法 给你一个arr 返回 T 或者 F arr的每个数代表从这个点开始跳几部,返回T的情况:从这个arr中任意一个数开始跳,可以在每个元素都跳到且只跳到一次的情况下返回到开始跳的元素 比如[1,1,1,1,1,1] => T [0,1,1,1,1,1]=> F [7, 5, 2, 3] => F [2,2,3,1] => T. From 1poi scan array once, get the index that can be reached by each arra…

Given a sorting order string, sort the input string based on the given sorting order string. Ex sorting order string -> dfbcae Input string -> abcdeeabc output -> dbbccaaee 法一:Comparable sample Input: String order = "dfbcae"; String str…