commit solution 171 205

Author: lxlxw

Diff for: index-tags.md

@@ -53,6 +53,7 @@
 |  [13](https://leetcode-cn.com/problems/roman-to-integer)  |  [罗马数字转整数](/solution/1-99/0013.roman-to-integer/)  |  `数学`,`字符串`  |  <font color=green>简单</font>  |✅ |
 |  [50](https://leetcode-cn.com/problems/powx-n)  |  [pow(x, n)](/solution/1-99/0050.pow%28x%2c-n%29/)  |  `数学`,`二分查找`  |  <font color=blue>中等</font>  |✅ |
 |  [69](https://leetcode-cn.com/problems/sqrtx)  |  [x 的平方根](/solution/1-99/0069.sqrt%28x%29/)  |  `数学`,`二分查找`  |  <font color=green>简单</font>  |✅ |
+|  [171](https://leetcode-cn.com/problems/excel-sheet-column-number)  |  [excel表列序号](/solution/100-199/0171.excel-sheet-column-number/)  |  `数学`  |  <font color=green>简单</font>  |✅ |
 |  [202](https://leetcode-cn.com/problems/happy-number)  |  [快乐数](/solution/200-299/0202.happy-number/)  |  `哈希表`,`数学`  |  <font color=green>简单</font>  |✅ |
 |  [204](https://leetcode-cn.com/problems/count-primes)  |  [计数质数](/solution/200-299/0204.count-primes/)  |  `哈希表`,`数学`  |  <font color=green>简单</font>  |✅ |
 |  [268](https://leetcode-cn.com/problems/missing-number)  |  [缺失数字](/solution/200-299/0268.missing-number/)  |  `位运算`,`数组`,`数学`  |  <font color=green>简单</font>  |✅ |
@@ -68,6 +69,7 @@
 |  [187](https://leetcode-cn.com/problems/repeated-dna-sequences)  |  [重复的dna序列](/solution/100-199/0187.repeated-dna-sequences/)  |  `位运算`,`哈希表`  |  <font color=blue>中等</font>  |✅ |
 |  [202](https://leetcode-cn.com/problems/happy-number)  |  [快乐数](/solution/200-299/0202.happy-number/)  |  `哈希表`,`数学`  |  <font color=green>简单</font>  |✅ |
 |  [204](https://leetcode-cn.com/problems/count-primes)  |  [计数质数](/solution/200-299/0204.count-primes/)  |  `哈希表`,`数学`  |  <font color=green>简单</font>  |✅ |
+|  [205](https://leetcode-cn.com/problems/isomorphic-strings)  |  [同构字符串](/solution/200-299/0205.isomorphic-strings/)  |  `哈希表`  |  <font color=green>简单</font>  |✅ |
 |  [217](https://leetcode-cn.com/problems/contains-duplicate)  |  [存在重复元素](/solution/200-299/0217.contains-duplicate/)  |  `数组`,`哈希表`  |  <font color=green>简单</font>  |✅ |
 |  [219](https://leetcode-cn.com/problems/contains-duplicate-ii)  |  [存在重复元素 ii](/solution/200-299/0219.contains-duplicate-ii/)  |  `数组`,`哈希表`  |  <font color=green>简单</font>  |✅ |
 

Diff for: index-type.md

@@ -49,7 +49,7 @@
 |  [168](https://leetcode-cn.com/problems/excel-sheet-column-title)  |  [excel表列名称](/solution/100-199/0168.excel-sheet-column-title/)  |  `数学`  |  <font color=green>简单</font>  |
 |  [169](https://leetcode-cn.com/problems/majority-element)  |  [多数元素](/solution/100-199/0169.majority-element/)  |  `位运算`,`数组`,`分治算法`  |  <font color=green>简单</font>  |✅ |
 |  [170](https://leetcode-cn.com/problems/two-sum-iii-data-structure-design)  |  [两数之和 iii - 数据结构设计](/solution/100-199/0170.two-sum-iii---data-structure-design/)  |  `设计`,`哈希表`  |  <font color=green>简单</font>  |
-|  [171](https://leetcode-cn.com/problems/excel-sheet-column-number)  |  [excel表列序号](/solution/100-199/0171.excel-sheet-column-number/)  |  `数学`  |  <font color=green>简单</font>  |
+|  [171](https://leetcode-cn.com/problems/excel-sheet-column-number)  |  [excel表列序号](/solution/100-199/0171.excel-sheet-column-number/)  |  `数学`  |  <font color=green>简单</font>  |✅ |
 |  [172](https://leetcode-cn.com/problems/factorial-trailing-zeroes)  |  [阶乘后的零](/solution/100-199/0172.factorial-trailing-zeroes/)  |  `数学`  |  <font color=green>简单</font>  |
 |  [175](https://leetcode-cn.com/problems/combine-two-tables)  |  [组合两个表](/solution/100-199/0175.combine-two-tables/)  |    |  <font color=green>简单</font>  |
 |  [176](https://leetcode-cn.com/problems/second-highest-salary)  |  [第二高的薪水](/solution/100-199/0176.second-highest-salary/)  |    |  <font color=green>简单</font>  |
@@ -67,7 +67,7 @@
 |  [202](https://leetcode-cn.com/problems/happy-number)  |  [快乐数](/solution/200-299/0202.happy-number/)  |  `哈希表`,`数学`  |  <font color=green>简单</font>  |✅ |
 |  [203](https://leetcode-cn.com/problems/remove-linked-list-elements)  |  [移除链表元素](/solution/200-299/0203.remove-linked-list-elements/)  |  `链表`  |  <font color=green>简单</font>  |
 |  [204](https://leetcode-cn.com/problems/count-primes)  |  [计数质数](/solution/200-299/0204.count-primes/)  |  `哈希表`,`数学`  |  <font color=green>简单</font>  |✅ |
-|  [205](https://leetcode-cn.com/problems/isomorphic-strings)  |  [同构字符串](/solution/200-299/0205.isomorphic-strings/)  |  `哈希表`  |  <font color=green>简单</font>  |
+|  [205](https://leetcode-cn.com/problems/isomorphic-strings)  |  [同构字符串](/solution/200-299/0205.isomorphic-strings/)  |  `哈希表`  |  <font color=green>简单</font>  |✅ |
 |  [206](https://leetcode-cn.com/problems/reverse-linked-list)  |  [反转链表](/solution/200-299/0206.reverse-linked-list/)  |  `链表`  |  <font color=green>简单</font>  |
 |  [217](https://leetcode-cn.com/problems/contains-duplicate)  |  [存在重复元素](/solution/200-299/0217.contains-duplicate/)  |  `数组`,`哈希表`  |  <font color=green>简单</font>  |✅ |
 |  [219](https://leetcode-cn.com/problems/contains-duplicate-ii)  |  [存在重复元素 ii](/solution/200-299/0219.contains-duplicate-ii/)  |  `数组`,`哈希表`  |  <font color=green>简单</font>  |✅ |

Diff for: solution/100-199/0171.excel-sheet-column-number/README.md

@@ -0,0 +1,54 @@
+# [171. Excel表列序号](https://leetcode-cn.com/problems/excel-sheet-column-number/description/)
+
+### 题目描述
+
+<p>给定一个Excel表格中的列名称，返回其相应的列序号。</p>
+
+<p>例如，</p>
+
+<pre>    A -&gt; 1
+    B -&gt; 2
+    C -&gt; 3
+    ...
+    Z -&gt; 26
+    AA -&gt; 27
+    AB -&gt; 28 
+    ...
+</pre>
+
+<p><strong>示例 1:</strong></p>
+
+<pre><strong>输入:</strong> &quot;A&quot;
+<strong>输出:</strong> 1
+</pre>
+
+<p><strong>示例&nbsp;2:</strong></p>
+
+<pre><strong>输入: </strong>&quot;AB&quot;
+<strong>输出:</strong> 28
+</pre>
+
+<p><strong>示例&nbsp;3:</strong></p>
+
+<pre><strong>输入: </strong>&quot;ZY&quot;
+<strong>输出:</strong> 701</pre>
+
+<p><strong>致谢：</strong><br>
+特别感谢&nbsp;<a href="http://leetcode.com/discuss/user/ts">@ts</a>&nbsp;添加此问题并创建所有测试用例。</p>
+
+### 解题思路
+
+### 具体解法
+
+#### **Golang**
+```go
+func titleToNumber(s string) int {
+	res := 0
+	for _, char := range s {
+		res *= 26
+		res += int(char-'A') + 1
+	}
+	return res
+}
+```
+

Diff for: solution/100-199/0171.excel-sheet-column-number/solution.go

@@ -0,0 +1,19 @@
+package leetcode
+
+/*
+ * @lc app=leetcode.cn id=171 lang=golang
+ *
+ * [171] Excel表列序号
+ */
+
+// @lc code=start
+func titleToNumber(s string) int {
+	res := 0
+	for _, char := range s {
+		res *= 26
+		res += int(char-'A') + 1
+	}
+	return res
+}
+
+// @lc code=end

Diff for: solution/100-199/0171.excel-sheet-column-number/solution_test.go

@@ -0,0 +1,28 @@
+package leetcode
+
+import (
+	"testing"
+)
+
+func TestTitleToNumber(t *testing.T) {
+	var ret int
+	var s string
+	ret = 1
+	s = "A"
+	if ret != titleToNumber(s) {
+		t.Fatalf("case fails %v\n", ret)
+	}
+
+	ret = 28
+	s = "AB"
+	if ret != titleToNumber(s) {
+		t.Fatalf("case fails %v\n", ret)
+	}
+
+	ret = 701
+	s = "ZY"
+	if ret != titleToNumber(s) {
+		t.Fatalf("case fails %v\n", ret)
+	}
+
+}

Diff for: solution/100-199/_sidebar.md

@@ -77,7 +77,7 @@
     - [168. excel表列名称](solution/100-199/0168.excel-sheet-column-title/)
     - [169. 多数元素 ✅](solution/100-199/0169.majority-element/)
     - [170. 两数之和 iii - 数据结构设计](solution/100-199/0170.two-sum-iii---data-structure-design/)
-    - [171. excel表列序号](solution/100-199/0171.excel-sheet-column-number/)
+    - [171. excel表列序号 ✅](solution/100-199/0171.excel-sheet-column-number/)
     - [172. 阶乘后的零](solution/100-199/0172.factorial-trailing-zeroes/)
     - [173. 二叉搜索树迭代器](solution/100-199/0173.binary-search-tree-iterator/)
     - [174. 地下城游戏](solution/100-199/0174.dungeon-game/)

Diff for: solution/200-299/0205.isomorphic-strings/README.md

@@ -0,0 +1,56 @@
+# [205. 同构字符串](https://leetcode-cn.com/problems/isomorphic-strings/description/)
+
+### 题目描述
+
+<p>给定两个字符串&nbsp;<em><strong>s&nbsp;</strong></em>和&nbsp;<strong><em>t</em></strong>，判断它们是否是同构的。</p>
+
+<p>如果&nbsp;<em><strong>s&nbsp;</strong></em>中的字符可以被替换得到&nbsp;<strong><em>t&nbsp;</em></strong>，那么这两个字符串是同构的。</p>
+
+<p>所有出现的字符都必须用另一个字符替换，同时保留字符的顺序。两个字符不能映射到同一个字符上，但字符可以映射自己本身。</p>
+
+<p><strong>示例 1:</strong></p>
+
+<pre><strong>输入:</strong> <strong><em>s</em></strong> = <code>&quot;egg&quot;, </code><strong><em>t = </em></strong><code>&quot;add&quot;</code>
+<strong>输出:</strong> true
+</pre>
+
+<p><strong>示例 2:</strong></p>
+
+<pre><strong>输入:</strong> <strong><em>s</em></strong> = <code>&quot;foo&quot;, </code><strong><em>t = </em></strong><code>&quot;bar&quot;</code>
+<strong>输出:</strong> false</pre>
+
+<p><strong>示例 3:</strong></p>
+
+<pre><strong>输入:</strong> <strong><em>s</em></strong> = <code>&quot;paper&quot;, </code><strong><em>t = </em></strong><code>&quot;title&quot;</code>
+<strong>输出:</strong> true</pre>
+
+<p><strong>说明:</strong><br>
+你可以假设&nbsp;<em><strong>s&nbsp;</strong></em>和 <strong><em>t </em></strong>具有相同的长度。</p>
+
+### 解题思路
+
+
+### 具体解法
+
+1. 设置`s`和`t`的`hash table`
+2. 遍历随意一个字符串
+3. 将遍历到的字符串的当作`key`, 字符串下标 `i+1` 当作`value`保存在`map`中
+4. 判断`map`中相同下标的字符串的对应下标位置是否相同
+
+#### **Golang**
+```go
+func isIsomorphic(s string, t string) bool {
+	sMap, tMap := map[uint8]int{}, map[uint8]int{}
+	for i := range s {
+		if sMap[s[i]] != tMap[t[i]] {
+			return false
+		} else {
+			sMap[s[i]] = i + 1
+			tMap[t[i]] = i + 1
+		}
+	}
+	return true
+}
+```
+
+

Diff for: solution/200-299/0205.isomorphic-strings/solution.go

@@ -0,0 +1,23 @@
+package leetcode
+
+/*
+ * @lc app=leetcode.cn id=205 lang=golang
+ *
+ * [205] 同构字符串
+ */
+
+// @lc code=start
+func isIsomorphic(s string, t string) bool {
+	sMap, tMap := map[uint8]int{}, map[uint8]int{}
+	for i := range s {
+		if sMap[s[i]] != tMap[t[i]] {
+			return false
+		} else {
+			sMap[s[i]] = i + 1
+			tMap[t[i]] = i + 1
+		}
+	}
+	return true
+}
+
+// @lc code=end

Diff for: solution/200-299/0205.isomorphic-strings/solution_test.go

@@ -0,0 +1,32 @@
+package leetcode
+
+import (
+	"testing"
+)
+
+func TestIsIsomorphic(t *testing.T) {
+	var ret bool
+	var s string
+	var ts string
+
+	ts = "add"
+	s = "egg"
+	ret = true
+	if ret != isIsomorphic(s, ts) {
+		t.Fatalf("case fails %v\n", ret)
+	}
+
+	ts = "bar"
+	s = "foo"
+	ret = false
+	if ret != isIsomorphic(s, ts) {
+		t.Fatalf("case fails %v\n", ret)
+	}
+
+	ts = "title"
+	s = "paper"
+	ret = true
+	if ret != isIsomorphic(s, ts) {
+		t.Fatalf("case fails %v\n", ret)
+	}
+}

Diff for: solution/200-299/_sidebar.md

@@ -11,7 +11,7 @@
     - [202. 快乐数 ✅](solution/200-299/0202.happy-number/)
     - [203. 移除链表元素](solution/200-299/0203.remove-linked-list-elements/)
     - [204. 计数质数 ✅](solution/200-299/0204.count-primes/)
-    - [205. 同构字符串](solution/200-299/0205.isomorphic-strings/)
+    - [205. 同构字符串 ✅](solution/200-299/0205.isomorphic-strings/)
     - [206. 反转链表](solution/200-299/0206.reverse-linked-list/)
     - [207. 课程表](solution/200-299/0207.course-schedule/)
     - [208. 实现 trie (前缀树)](solution/200-299/0208.implement-trie-prefix-tree/)