string tag

Author: jackzhenguo

Stack/Stack/Stack.v12.suo

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StringSln.Lib
+{
+    public class DetectCapitalSln
+    {
+        //        Given a word, you need to judge whether the usage of capitals in it is right or not.
+
+        //We define the usage of capitals in a word to be right when one of the following cases holds:
+
+        //All letters in this word are capitals, like “USA”. 
+        //All letters in this word are not capitals, like “leetcode”. 
+        //Only the first letter in this word is capital if it has more than one letter, like “Google”. 
+        //Otherwise, we define that this word doesn’t use capitals in a right way.
+
+        //Example 1:
+        //Input: "USA"
+        //Output: True
+
+        //Example 2:
+        //Input: "FlaG"
+        //Output: False
+
+        public bool DetectCapitalUse(string word)
+        {
+            if (string.IsNullOrEmpty(word)) return true;
+
+            char fst = word[0];
+            if (charCapital(fst))
+            {
+                int afterCapital = 0;
+                for (int i = 1; i < word.Length; i++)
+                {
+                    if (charCapital(word[i]))
+                        afterCapital++;
+                }
+                if (afterCapital == 0)
+                    return true;//只有首字符大写
+                else if (afterCapital == word.Length - 1)
+                    return true;//都是大写
+                return false;
+            }
+            else//首字符小写
+            {
+                int afterCapotal = 0;
+                for (int i = 1; i < word.Length; i++)
+                {
+                    if (charCapital(word[i]))
+                        afterCapotal++;
+                }
+                return afterCapotal == 0 ? true : false;
+            }
+
+        }
+
+        private bool charCapital(char ch)
+        {
+            int chint = Convert.ToInt32(ch);
+            if (chint >= 65 && chint <= 90)
+                return true;
+            return false;
+        }
+    }
+}

String/StringSln.Lib/DetectCapitalSln.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StringSln.Lib
+{
+    //    Given a string s consists of upper/lower-case alphabets and empty space characters ’ ‘, return the length of last word in the string.
+
+    //If the last word does not exist, return 0.
+
+    //Note: A word is defined as a character sequence consists of non-space characters only.
+
+    //For example,
+
+    //Given s = "Hello World",
+    //return 5.
+    public class LengthOfLastWordSln
+    {
+        public int LengthOfLastWord(string s)
+        {
+            s = s.Trim();
+            if (s == "") return 0;
+            for (int i = s.Length - 1; i > 0; i--)
+            {
+                if (s[i] == ' ')
+                    return s.Length - i - 1;
+            }
+            return s.Length;
+        }
+        public int LengthOfLastWord2(string s)
+        {
+            s = s.Trim(); //去掉前，后空格
+            if (s == "") return 0;
+            string[] splitstring = s.Split(' ');
+            string slast = splitstring[splitstring.Length - 1];
+            return slast.Length == 0 ? 1 : slast.Length;
+        }
+    }
+}

String/StringSln.Lib/LengthOfLastWordSln.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StringSln.Lib
+{
+    public class LongestCommonPrefixSln
+    {
+        public string LongestCommonPrefix(string[] strs)
+        {
+            if (strs == null || strs.Length == 0)
+                return "";
+            if (strs.Length == 1)
+                return strs[0];
+
+            string longestPrefix = firstTwoStrs(strs);
+            if (longestPrefix.Length == 0)
+                return "";
+            int i = 2;
+            while (i < strs.Length)
+            {
+                if (strs[i].IndexOf(longestPrefix) != 0)
+                {
+                    longestPrefix =
+                    longestPrefix.Substring(0, longestPrefix.Length - 1);
+                    i = 1;
+                    if (longestPrefix.Length == 0)
+                        return "";
+                }
+                i++;
+            }
+            return longestPrefix;
+        }
+
+        //头两个字符串的公共串
+        private string firstTwoStrs(string[] strs)
+        {
+            if (strs.Length < 2) return "";
+            StringBuilder sb = new StringBuilder();
+            int len = strs[0].Length < strs[1].Length ? strs[0].Length : strs[1].Length;
+            for (int i = 0; i < len; i++)
+            {
+                if (strs[0][i] == strs[1][i])
+                    sb.Append(strs[0][i]);
+                else
+                    break;
+            }
+            return sb.ToString();
+        }
+    }
+}

String/StringSln.Lib/LongestCommonPrefixSln.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// 有关程序集的常规信息通过以下
+// 特性集控制。更改这些特性值可修改
+// 与程序集关联的信息。
+[assembly: AssemblyTitle("StringSln.Lib")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("StringSln.Lib")]
+[assembly: AssemblyCopyright("Copyright ©  2017")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// 将 ComVisible 设置为 false 使此程序集中的类型
+// 对 COM 组件不可见。  如果需要从 COM 访问此程序集中的类型，
+// 则将该类型上的 ComVisible 特性设置为 true。
+[assembly: ComVisible(false)]
+
+// 如果此项目向 COM 公开，则下列 GUID 用于类型库的 ID
+[assembly: Guid("3f2eba77-d506-477a-ac13-da11cc28296b")]
+
+// 程序集的版本信息由下面四个值组成: 
+//
+//      主版本
+//      次版本 
+//      生成号
+//      修订号
+//
+// 可以指定所有这些值，也可以使用“生成号”和“修订号”的默认值，
+// 方法是按如下所示使用“*”: 
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

String/StringSln.Lib/Properties/AssemblyInfo.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StringSln.Lib
+{
+    //    Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it will return false.
+
+    //Each letter in the magazine string can only be used once in your ransom note.
+
+    //Note: 
+    //You may assume that both strings contain only lowercase letters.
+
+    //canConstruct("a", "b") -> false
+    //canConstruct("aa", "ab") -> false
+    //canConstruct("aa", "aab") -> true
+    //canConstruct("fffbfg","effjfggbffjdgbjjhhdegh") ->true
+    public class RansomNoteSln
+    {
+        public bool CanConstruct(string ransomNote, string magazine)
+        {
+            if (magazine == null && ransomNote == null) return true;
+            if (magazine == null) return false;
+
+            //magazine字符串整理为字典
+            Dictionary<char, int> dict = new Dictionary<char, int>();
+            foreach (var item in magazine)
+            {
+                if (dict.ContainsKey(item))
+                    dict[item]++;
+                else dict.Add(item, 1);
+            }
+
+            foreach (var item in ransomNote)
+            {
+                if (!dict.ContainsKey(item))//未出现直接返回false
+                    return false;
+                dict[item]--;
+                if (dict[item] == 0) //为0后，移除
+                    dict.Remove(item);
+            }
+
+            return true;
+        }
+    }
+}

String/StringSln.Lib/RansomNoteSln.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StringSln.Lib
+{
+    public class RepeatedSubstringSln
+    {
+        //        Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 10000.
+
+        //Example 1:
+        //Input: "abab"
+
+        //Output: True
+
+        //Explanation: It's the substring "ab" twice.
+
+        //Example 2:
+        //Input: "aba"
+
+        //Output: False
+
+        //Example 3:
+        //Input: "abcabcabcabc"
+
+        //Output: True
+
+        //Explanation: It's the substring "abc" four times. (And the substring "abcabc" twice.)
+
+        public bool RepeatedSubstringPattern(string s)
+        {
+            for (int i = s.Length / 2; i > 0; i--)
+            {
+                if (s.Length % i != 0)
+                    continue;
+                string prefix = s.Substring(0, i); //可能的重复子串
+                string strsub = s.Substring(i); //去掉以上可能的重复子串后
+                int index = strsub.IndexOf(prefix);
+                if (index != 0)
+                    continue;
+                else //表明紧接着字符串匹配上
+                {
+                    //用这个子串重复s.Length/i次，若与原串相等，便为true。
+                    StringBuilder sb = new StringBuilder();
+                    for (int j = 0; j < s.Length / i; j++)
+                        sb.Append(prefix);
+                    if (sb.ToString() == s)
+                        return true;
+                }
+
+            }
+            return false;
+        }
+    }
+}

String/StringSln.Lib/RepeatedSubstringSln.cs

@@ -0,0 +1,70 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StringSln.Lib
+{
+    public class SegmentNumberSln
+    {
+        //        Count the number of segments in a string, where a segment is defined to be a contiguous sequence of non-space characters.
+
+        //Please note that the string does not contain any non-printable characters.
+
+        //Example:
+
+        //Input: "Hello, my name is John"
+        //Output: 5
+
+        //Input: "          "
+        //Output: 0
+
+        //Input: "     a"
+        //Output: 1
+
+        //Input: "     a        "
+        //Output: 1
+
+        //Input: "     a                b    "
+        //Output: 2
+
+        public int CountSegments(string s)
+        {
+            if (string.IsNullOrEmpty(s))
+                return 0;
+            int i = 0;
+            while (i < s.Length && !isValidBegin(s[i]))
+                i++;
+            if (i == s.Length) //没有有效字符，如"         "
+                return 0;
+            if (i == s.Length - 1)  //只有一个有效字符，如 "         a"
+                return 1;
+            while (i < s.Length - 1 && !isValidEnd(s[i], s[i + 1]))
+                i++;
+            if (i == s.Length - 1)
+                return 1; //只有1个有效字符，如"         a              "
+
+            return 1 + CountSegments(s.Substring(i + 1));
+        }
+
+        //字符串的第一个片段的首字符，找到有效字符开始
+        private bool isValidBegin(char curchar)
+        {
+            if (curchar != ' ')
+                return true;
+            return false;
+        }
+
+
+        //判断字符片段的结束
+        private bool isValidEnd(char curchar, char afterchar)
+        {
+            if (curchar != ' ' && afterchar == ' ')
+                return true;
+            return false;
+        }
+
+
+    }
+}