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atwood
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solve last hard string question
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‎No30_String.cs

+166
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using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Text;
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namespace LeetCode_30
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{
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//static void Main(string[] args)
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//{
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// var solution = new Solution();
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// while (true)
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// {
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// //int input = int.Parse(Console.ReadLine());
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// //int input2 = int.Parse(Console.ReadLine());
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// //int input3 = int.Parse(Console.ReadLine());
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// //string input = Console.ReadLine();
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// //string input2 = Console.ReadLine();
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// //int[] intArr = input.Split(',').Select(s => int.Parse(s)).ToArray();
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// //int input2 = int.Parse(Console.ReadLine());
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// //int?[] data = new int?[] { 6, 2, 8, 0, 4, 7, 9, null, null, 3, 5 };
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// //int?[] data = new int?[] { 1, null, 2, 3 };
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// //int?[] data = new int?[] { 1, 2, 2, 3, 3, null, null, 4, 4 };
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// //int?[] data = new int?[] { 1, 2, null, 3 };
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// //int?[] data = new int?[] { 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, null, null, 5, 5 };
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// //var tree = new DataStructureBuilder().BuildTree(data);
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// //var res = solution.FindSubstring("barfoothefoobarman", new string[] { "foo", "bar" });
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// //var res = solution.FindSubstring("wordgoodgoodgoodbestword", new string[] { "word", "good", "best", "word" });
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// //var res = solution.FindSubstring("", new string[] { });
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// var res = solution.FindSubstring("barfoofoobarthefoobarman", new string[] { "bar", "foo", "the" });
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// //var res = solution.FindSubstring("pjzkrkevzztxductzzxmxsvwjkxpvukmfjywwetvfnujhweiybwvvsrfequzkhossmootkmyxgjgfordrpapjuunmqnxxdrqrfgkrsjqbszgiqlcfnrpjlcwdrvbumtotzylshdvccdmsqoadfrpsvnwpizlwszrtyclhgilklydbmfhuywotjmktnwrfvizvnmfvvqfiokkdprznnnjycttprkxpuykhmpchiksyucbmtabiqkisgbhxngmhezrrqvayfsxauampdpxtafniiwfvdufhtwajrbkxtjzqjnfocdhekumttuqwovfjrgulhekcpjszyynadxhnttgmnxkduqmmyhzfnjhducesctufqbumxbamalqudeibljgbspeotkgvddcwgxidaiqcvgwykhbysjzlzfbupkqunuqtraxrlptivshhbihtsigtpipguhbhctcvubnhqipncyxfjebdnjyetnlnvmuxhzsdahkrscewabejifmxombiamxvauuitoltyymsarqcuuoezcbqpdaprxmsrickwpgwpsoplhugbikbkotzrtqkscekkgwjycfnvwfgdzogjzjvpcvixnsqsxacfwndzvrwrycwxrcismdhqapoojegggkocyrdtkzmiekhxoppctytvphjynrhtcvxcobxbcjjivtfjiwmduhzjokkbctweqtigwfhzorjlkpuuliaipbtfldinyetoybvugevwvhhhweejogrghllsouipabfafcxnhukcbtmxzshoyyufjhzadhrelweszbfgwpkzlwxkogyogutscvuhcllphshivnoteztpxsaoaacgxyaztuixhunrowzljqfqrahosheukhahhbiaxqzfmmwcjxountkevsvpbzjnilwpoermxrtlfroqoclexxisrdhvfsindffslyekrzwzqkpeocilatftymodgztjgybtyheqgcpwogdcjlnlesefgvimwbxcbzvaibspdjnrpqtyeilkcspknyylbwndvkffmzuriilxagyerjptbgeqgebiaqnvdubrtxibhvakcyotkfonmseszhczapxdlauexehhaireihxsplgdgmxfvaevrbadbwjbdrkfbbjjkgcztkcbwagtcnrtqryuqixtzhaakjlurnumzyovawrcjiwabuwretmdamfkxrgqgcdgbrdbnugzecbgyxxdqmisaqcyjkqrntxqmdrczxbebemcblftxplafnyoxqimkhcykwamvdsxjezkpgdpvopddptdfbprjustquhlazkjfluxrzopqdstulybnqvyknrchbphcarknnhhovweaqawdyxsqsqahkepluypwrzjegqtdoxfgzdkydeoxvrfhxusrujnmjzqrrlxglcmkiykldbiasnhrjbjekystzilrwkzhontwmehrfsrzfaqrbbxncphbzuuxeteshyrveamjsfiaharkcqxefghgceeixkdgkuboupxnwhnfigpkwnqdvzlydpidcljmflbccarbiegsmweklwngvygbqpescpeichmfidgsjmkvkofvkuehsmkkbocgejoiqcnafvuokelwuqsgkyoekaroptuvekfvmtxtqshcwsztkrzwrpabqrrhnlerxjojemcxel", new string[] { "dhvf", "sind", "ffsl", "yekr", "zwzq", "kpeo", "cila", "tfty", "modg", "ztjg", "ybty", "heqg", "cpwo", "gdcj", "lnle", "sefg", "vimw", "bxcb" });
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// ConsoleX.WriteLine(res);
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// }
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//}
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public class Solution
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{
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/// <summary>
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/// 滑动窗口（Sliding Window），不会退，一边进一边出，一次遍历就解决
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/// s长度为n，单词个数t
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/// 时间复杂度：O(n)
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/// 空间复杂度：O(t),维护两个dictionary用于匹配
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/// </summary>
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/// <param name="s"></param>
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/// <param name="words"></param>
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/// <returns></returns>
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public IList<int> FindSubstring(string s, string[] words)
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{
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IList<int> res = new List<int>();
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//如果长度都小于匹配数组总长度，则一定不匹配
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int tlen = words.Sum(t => t.Length);
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if (s == null || s.Length < tlen || words.Length == 0)
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return res;
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//单词和单词出现的频率
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Dictionary<string, int> dic = new Dictionary<string, int>();
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foreach (string word in words)
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{
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InsertOrAdd(dic, word);
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}
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//有一个题目上没有的隐含条件，word都是等长的
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int wordLen = words[0].Length;
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for (int i = 0; i < wordLen; i++)
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{
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Dictionary<string, int> temp = new Dictionary<string, int>();
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//其实可以不要这个参数，不过这样的话就要每次都去比对两个dictionary了，性能不好
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int validWordCount = 0;
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for (int j = i; j + wordLen <= s.Length; j += wordLen)
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{
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//如果大于等于words总长，开始滑出（弹出一个word）
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if (j - i >= tlen)
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{
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string outWord = s.Substring(j - tlen, wordLen);
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if (dic.ContainsKey(outWord))
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{
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validWordCount--;
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RemoveOrReduce(temp, outWord);
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}
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}
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//滑入
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string inWord = s.Substring(j, wordLen);
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if (dic.ContainsKey(inWord))
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{
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validWordCount++;
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InsertOrAdd(temp, inWord);
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}
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if (validWordCount == words.Length && CompareTwoDic(dic, temp))
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res.Add(j + wordLen - tlen);
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}
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}
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return res;
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}
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private bool CompareTwoDic(Dictionary<string, int> dic1, Dictionary<string, int> dic2)
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{
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//Knowledge：两个dictionary的对比方法：dic1.Count == dic2.Count && !dic1.Except(dic2).Any()，key，value都会做比较。
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return dic1.Count == dic2.Count && !dic1.Except(dic2).Any();
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}
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private void InsertOrAdd(Dictionary<string, int> dic, string word)
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{
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if (!dic.ContainsKey(word))
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dic.Add(word, 1);
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else
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dic[word]++;
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}
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private void RemoveOrReduce(Dictionary<string, int> dic, string word)
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{
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if (dic[word] <= 1)
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dic.Remove(word);
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else
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dic[word]--;
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}
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/// <summary>
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/// 第一反应解，算出所有组合，然后通过带匹配字符串的hash去比对。超时，算了一下组合，数量指数级上升，故不可行
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/// s长度为n，words的个数为m
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/// 时间复杂度：O(m!),构建组合花了绝大部分时间，遍历的话只需要n，在m小的情况下这个算法是可行的
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/// 空间复杂度：O(m!)
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/// 刚看到超时，还想用滚动hash优化一下的，debug一下结果发现是在拼接组合中就超时了
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/// </summary>
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/// <param name="s"></param>
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/// <param name="words"></param>
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/// <returns></returns>
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//public IList<int> FindSubstring(string s, string[] words)
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//{
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// IList<int> res = new List<int>();
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// //如果长度都小于匹配数组总长度，则一定不匹配
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// int tlen = words.Sum(t => t.Length);
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// if (s == null || s.Length < tlen || words.Length == 0)
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// return res;
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// //构建所有组合的字典
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// RecursiveDicBuild(string.Empty, words.ToList());
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// //和所有组合逐个比对hash
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// for (int i = 0; i <= s.Length - tlen; i++)
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// {
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// string cur = s.Substring(i, tlen);
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// int curHash = cur.GetHashCode();
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// if (_dic.ContainsKey(curHash) && _dic[curHash] == cur)
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// res.Add(i);
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// }
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// return res;
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//}
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////构建一个装所有数组匹配可能性的字典，key是组合的hashcode，string是组合内容
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//private Dictionary<int, string> _dic = new Dictionary<int, string>();
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//private void RecursiveDicBuild(string str, List<string> strList)
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//{
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// if (strList == null || strList.Count == 0)
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// {
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// if (!_dic.ContainsKey(str.GetHashCode()))
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// _dic.Add(str.GetHashCode(), str);
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// }
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// else
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// {
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// for (int i = 0; i < strList.Count; i++)
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// {
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// string curStr = strList[i];
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// var restStrList = strList.ToList();
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// restStrList.RemoveAt(i);
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// RecursiveDicBuild(str + curStr, restStrList);
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// }
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// }
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//}
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}
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}

‎Program.cs

+4-1
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@@ -28,14 +28,17 @@ static void Main(string[] args)
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//int?[] data = new int?[] { 1, 2, null, 3 };
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//int?[] data = new int?[] { 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, null, null, 5, 5 };
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//var tree = new DataStructureBuilder().BuildTree(data);
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var res = solution.QuickSort(new int[] { 5, 2, 4, 1, 3, 6, 0 }, 4);
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var res = solution.GenerateTrees(6);
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ConsoleX.WriteLine(res);
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}
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}
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public class Solution
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{
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public IList<TreeNode> GenerateTrees(int n)
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{
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}
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}
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}
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}

‎README.md

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| 78 | 77585 |
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| 81 | 74976 |
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| 82 | 74300 |
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| 82 | 74596 |
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刚好因为有一天在深入之前的算法，没有做新题，发现了有296人在这一天刷到了84以上。

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