Leetcode: Clone Graph

2014-11-24 00:40:37 · 作者: · 浏览: 4
Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors.
OJ's undirected graph serialization:
Nodes are labeled uniquely.
We use # as a separator for each node, and , as a separator for node label and each neighbor of the node.
As an example, consider the serialized graph {0,1,2#1,2#2,2}.
The graph has a total of three nodes, and therefore contains three parts as separated by #.
First node is labeled as 0. Connect node 0 to both nodes 1 and 2.
Second node is labeled as 1. Connect node 1 to node 2.
Third node is labeled as 2. Connect node 2 to node 2 (itself), thus forming a self-cycle.
Visually, the graph looks like the following:
1
/ \
/ \
0 --- 2
/ \
\_/
/** 
 * Definition for undirected graph. 
 * struct UndirectedGraphNode { 
 *     int label; 
 *     vector neighbors; 
 *     UndirectedGraphNode(int x) : label(x) {}; 
 * }; 
 */  
class Solution {  
public:  
   UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {  
        // Note: The Solution object is instantiated only once.  
        if(node == NULL)return NULL;  
  
        queue
qu; qu.push(node); set st; while(!qu.empty()) { UndirectedGraphNode* curnode = qu.front(); qu.pop(); if(st.find(curnode) != st.end()) continue; st.insert(curnode); vector::iterator it = curnode->neighbors.begin(); while(it != curnode->neighbors.end()) { qu.push(*it); it++; } } map graphmp; set::iterator sit = st.begin(); for(;sit!=st.end();sit++) { UndirectedGraphNode* tmp = new UndirectedGraphNode((*sit)->label); graphmp[*sit] = tmp; } sit = st.begin(); for(;sit!=st.end();sit++) { UndirectedGraphNode* tmp = graphmp[*sit]; vector::iterator vit = (*sit)->neighbors.begin(); while(vit != (*sit)->neighbors.end()) { tmp->neighbors.push_back(graphmp[(*vit)]); vit++; } } return graphmp[node]; } };