Merge pull request #2366 from eeee0717/master

Update0131.分割回文串

problems/0040.组合总和II.md

@@ -773,7 +773,39 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public List<IList<int>> res = new List<IList<int>>();
+    public List<int> path = new List<int>();
+    public IList<IList<int>> CombinationSum2(int[] candidates, int target)
+    {
 
+        Array.Sort(candidates);
+        BackTracking(candidates, target, 0, 0);
+        return res;
+    }
+    public void BackTracking(int[] candidates, int target, int start, int sum)
+    {
+        if (sum > target) return;
+        if (sum == target)
+        {
+            res.Add(new List<int>(path));
+            return;
+        }
+        for (int i = start; i < candidates.Length && sum + candidates[i] <= target; i++)
+        {
+            if (i > start && candidates[i] == candidates[i - 1]) continue;
+            sum += candidates[i];
+            path.Add(candidates[i]);
+            BackTracking(candidates, target, i + 1, sum);
+            sum -= candidates[i];
+            path.RemoveAt(path.Count - 1);
+        }
+    }
+}
+```
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problems/0093.复原IP地址.md

@@ -799,6 +799,53 @@ object Solution {
   }
 }
 ```
+### C#
+```csharp
+public class Solution
+{
+    public IList<string> res = new List<string>();
+    public IList<string> RestoreIpAddresses(string s)
+    {
+        if (s.Length < 4 || s.Length > 12) return res;
+        BackTracking(s, 0, 0);
+        return res;
+    }
+    public void BackTracking(string s, int start, int pointSum)
+    {
+        if (pointSum == 3)
+        {
+            if (IsValid(s, start, s.Length - 1))
+            {
+                res.Add(s);
+            }
+            return;
+        }
+        for (int i = start; i < s.Length; i++)
+        {
+            if (IsValid(s, start, i))
+            {
+                s = s.Insert(i + 1, ".");
+                BackTracking(s, i + 2, pointSum + 1);
+                s = s.Remove(i + 1, 1);
+            }
+            else break;
+        }
+    }
+    public bool IsValid(string s, int start, int end)
+    {
+        if (start > end) return false;
+        if (s[start] == '0' && start != end) return false;
+        int num = 0;
+        for (int i = start; i <= end; i++)
+        {
+            if (s[i] > '9' || s[i] < '0') return false;
+            num = num * 10 + s[i] - '0';
+            if (num > 255) return false;
+        }
+        return true;
+    }
+}
+```
 
 
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problems/0131.分割回文串.md

@@ -847,6 +847,50 @@ object Solution {
   }
 }
 ```
+### CSharp
+```csharp
+public class Solution
+{
+    public IList<IList<string>> res = new List<IList<string>>();
+    public IList<string> path = new List<string>();
+    public IList<IList<string>> Partition(string s)
+    {
+        BackTracking(s, 0);
+        return res;
+    }
+    public void BackTracking(string s, int start)
+    {
+        if (start >= s.Length)
+        {
+            res.Add(new List<string>(path));
+            return;
+        }
+
+        for (int i = start; i < s.Length; i++)
+        {
+            if (IsPalindrome(s, start, i))
+            {
+                path.Add(s.Substring(start, i - start + 1));
+            }
+            else
+            {
+                continue;
+            }
+            BackTracking(s, i + 1);
+            path.RemoveAt(path.Count - 1);
+        }
+    }
+    public bool IsPalindrome(string s, int start, int end)
+    {
+        for (int i = start, j = end; i < j; i++, j--)
+        {
+            if (s[i] != s[j])
+                return false;
+        }
+        return true;
+    }
+}
+```
 
 
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