"Clone Graph"

Author: lennylxx

README.md

@@ -167,7 +167,7 @@ The `☢` means that you need to have a LeetCode Premium Subscription.
 | 136 | [Single Number]                                              | [C](src/136.c)     |
 | 135 | [Candy]                                                      |                    |
 | 134 | [Gas Station]                                                |                    |
-| 133 | [Clone Graph]                                                |                    |
+| 133 | [Clone Graph]                                                | [C++](src/133.cpp) |
 | 132 | [Palindrome Partitioning II]                                 |                    |
 | 131 | [Palindrome Partitioning]                                    |                    |
 | 130 | [Surrounded Regions]                                         |                    |

src/133.cpp

@@ -0,0 +1,78 @@
+#include <iostream>
+#include <vector>
+#include <map>
+
+using namespace std;
+
+struct UndirectedGraphNode {
+    int label;
+    vector<UndirectedGraphNode *> neighbors;
+    UndirectedGraphNode(int x) : label(x) {};
+};
+
+class Solution {
+    map<UndirectedGraphNode *, UndirectedGraphNode *> copyMap;
+public:
+    UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {
+        if (node == NULL) return NULL;
+        return dfs(node);
+    }
+
+    UndirectedGraphNode* dfs(UndirectedGraphNode *node) {
+        UndirectedGraphNode *new_node = new UndirectedGraphNode(node->label);
+        copyMap[node] = new_node;
+        for (auto u : node->neighbors) {
+            if (copyMap[u]) {
+                new_node->neighbors.push_back(copyMap[u]);
+            }
+            else {
+                new_node->neighbors.push_back(dfs(u));
+            }
+        }
+        return new_node;
+    }
+
+    void printGraph(UndirectedGraphNode *node) {
+        map<UndirectedGraphNode *, bool> visited;
+        printHelper(visited, node);
+        printf("\n");
+    }
+
+    void printHelper(map<UndirectedGraphNode *, bool> &visited, UndirectedGraphNode *node) {
+        if (node == NULL) return;
+        if (visited[node]) return;
+
+        printf("%d", node->label);
+        for (auto u : node->neighbors) {
+            printf(",%d", u->label);
+        }
+        printf("#");
+        visited[node] = true;
+
+        for (auto u : node->neighbors) {
+            printHelper(visited, u);
+        }
+    }
+};
+
+int main() {
+
+    UndirectedGraphNode *zero = new UndirectedGraphNode(0);
+    UndirectedGraphNode *one = new UndirectedGraphNode(1);
+    UndirectedGraphNode *two = new UndirectedGraphNode(2);
+
+    zero->neighbors = { one, two };
+    one->neighbors = { two };
+    two->neighbors = { two };
+
+    Solution s;
+    printf(" Graph: ");
+    s.printGraph(zero);
+
+    UndirectedGraphNode *cloned = s.cloneGraph(zero);
+
+    printf("Cloend: ");
+    s.printGraph(cloned);
+
+    return 0;
+}