From c681ec887a1f4d4fb0efdd5c9acde33e23582978 Mon Sep 17 00:00:00 2001
From: Yang Wang <AngYony@163.com>
Date: Fri, 20 Dec 2019 17:00:44 +0800
Subject: [PATCH] =?UTF-8?q?Week8=20=E4=BD=9C=E4=B8=9A?=
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Week8作业
---
 Week 08/id_546/LeetCode_1143_546.cs | 37 +++++++++++++++
 Week 08/id_546/LeetCode_5_546.cs    | 36 +++++++++++++++
 Week 08/id_546/LeetCode_72_546.cs   | 70 +++++++++++++++++++++++++++++
 3 files changed, 143 insertions(+)
 create mode 100644 Week 08/id_546/LeetCode_1143_546.cs
 create mode 100644 Week 08/id_546/LeetCode_5_546.cs
 create mode 100644 Week 08/id_546/LeetCode_72_546.cs

diff --git a/Week 08/id_546/LeetCode_1143_546.cs b/Week 08/id_546/LeetCode_1143_546.cs
new file mode 100644
index 000000000..2fad87c3f
--- /dev/null
+++ b/Week 08/id_546/LeetCode_1143_546.cs	
@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Medium
+{
+    public class LongestCommonSubsequence
+    {
+        public int LongestCommonSubsequence1(string text1, string text2)
+        {
+            int[,] dp = new int[text1.Length + 1, text2.Length + 1];
+                       
+
+            for (int i = 1; i < text1.Length + 1; i++)
+            {
+                for (int j = 1; j < text2.Length + 1; j++)
+                {
+                    //如果末端相同
+                    if (text1[i - 1] == text2[j - 1])
+                    {
+                        dp[i,j] = dp[i - 1,j - 1] + 1;
+                    }
+                    else
+                    {
+                        //如果末端不同
+                        dp[i,j] = Math.Max(dp[i - 1,j], dp[i,j - 1]);
+                    }
+                }
+            }
+            return dp[text1.Length,text2.Length];
+
+          
+        }
+    }
+}
diff --git a/Week 08/id_546/LeetCode_5_546.cs b/Week 08/id_546/LeetCode_5_546.cs
new file mode 100644
index 000000000..64a145da9
--- /dev/null
+++ b/Week 08/id_546/LeetCode_5_546.cs	
@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Medium
+{
+    public class LongestPalindromicSubstring
+    {
+        public string LongestPalindrome(string s)
+        {
+            int n = s.Length;
+            string res = "";
+            bool[,] dp = new bool[n,n];
+            for (int i = n - 1; i >= 0; i--)
+            {
+                for (int j = i; j < n; j++)
+                {
+                    dp[i,j] = s[i] == s[j] && (j - i < 2 || dp[i + 1,j - 1]); //j - i 代表长度减去 1        
+                    if (dp[i,j] && j - i + 1 > res.Length)
+                    {
+                        res = s.Substring(i, j + 1-i);
+                    }
+                }
+            }
+            return res;
+
+
+            
+
+
+
+        }
+    }
+}
diff --git a/Week 08/id_546/LeetCode_72_546.cs b/Week 08/id_546/LeetCode_72_546.cs
new file mode 100644
index 000000000..da4413e42
--- /dev/null
+++ b/Week 08/id_546/LeetCode_72_546.cs	
@@ -0,0 +1,70 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Hard
+{
+    /// <summary>
+    /// 72. 编辑距离
+    /// </summary>
+    public class EditDistance
+    {
+        //推荐解法
+        public int MinDistance(string word1, string word2)
+        {
+            int m = word1.Length;
+            int n = word2.Length;
+
+            int[,] cost = new int[m + 1, n + 1];
+            for (int i = 0; i <= m; i++)
+                cost[i, 0] = i;
+            for (int i = 1; i <= n; i++)
+                cost[0, i] = i;
+
+            for (int i = 0; i < m; i++)
+            {
+                for (int j = 0; j < n; j++)
+                {
+                    if (word1[i] == word2[j])
+                        cost[i + 1, j + 1] = cost[i, j];
+                    else
+                    {
+                        int a = cost[i, j];
+                        int b = cost[i, j + 1];
+                        int c = cost[i + 1, j];
+                        cost[i + 1, j + 1] = a < b ? (a < c ? a : c) : (b < c ? b : c);
+                        cost[i + 1, j + 1]++;
+                    }
+                }
+            }
+            return cost[m, n];
+        }
+
+
+        public int minDistance(String word1, String word2)
+        {
+            int n1 = word1.Length;
+            int n2 = word2.Length;
+            int[,] dp = new int[n1 + 1, n2 + 1];
+
+
+            // 第一行
+            for (int j = 1; j <= n2; j++) dp[0, j] = dp[0, j - 1] + 1;
+            // 第一列
+            for (int i = 1; i <= n1; i++) dp[i, 0] = dp[i - 1, 0] + 1;
+
+            for (int i = 1; i <= n1; i++)
+            {
+                for (int j = 1; j <= n2; j++)
+                {
+                    if (word1[i - 1] == word2[j - 1]) dp[i, j] = dp[i - 1, j - 1];
+                    else dp[i, j] = Math.Min(Math.Min(dp[i - 1, j - 1], dp[i, j - 1]), dp[i - 1, j]) + 1;
+                }
+            }
+            return dp[n1, n2];
+        }
+
+    }
+}