Create Readme.md

wisdompeak · web-flow · commit d5384266ff84 · 2021-01-27T20:55:48.000-08:00
diff --git a/Graph/1059.All-Paths-from-Source-Lead-to-Destination/Readme.md b/Graph/1059.All-Paths-from-Source-Lead-to-Destination/Readme.md
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+### 1059.All-Paths-from-Source-Lead-to-Destination
+
+此题的本质是用DFS来检查图内是否有环。模板如下：
+```
+    bool dfs(int cur)
+    {
+        visited[cur] = 2;
+        for (int next: graph[cur])
+        {
+            if (visited[next]==1) continue;
+            if (visited[next]==2) return false;
+            if (dfs(next)==false)  return false;
+        }
+        visited[cur] = 1;
+        return true;
+    }
+```
+
+另外，如果DFS到了端点节点，还要检查是否是destination。
