Merge pull request #2279 from Snow-Ye/master

添加了684.冗余连接 的Python并查集简洁写法 ， 添加了 1971. 寻找图中是否存在路径 的Python并查集解法

problems/0684.冗余连接.md

@@ -256,6 +256,23 @@ class Solution:
         return []
 ```
 
+### Python简洁写法：
+
+```python
+class Solution:
+    def findRedundantConnection(self, edges: List[List[int]]) -> List[int]:
+        n = len(edges)
+        p = [i for i in range(n+1)]
+        def find(i):
+            if p[i] != i:
+                p[i] = find(p[i])
+            return p[i]
+        for u, v in edges:
+            if p[find(u)] == find(v):
+                return [u, v]
+            p[find(u)] = find(v)
+```
+
 ### Go
 
 ```go

problems/1971.寻找图中是否存在路径.md

@@ -134,6 +134,22 @@ public:
     }
 };
 ```
+
+PYTHON并查集解法如下：
+```PYTHON
+class Solution:
+    def validPath(self, n: int, edges: List[List[int]], source: int, destination: int) -> bool:
+        p = [i for i in range(n)]
+        def find(i):
+            if p[i] != i:
+                p[i] = find(p[i])
+            return p[i]
+        for u, v in edges:
+            p[find(u)] = find(v)
+        return find(source) == find(destination)
+```
+
+
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