Clone Graph

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 #.

1. First node is labeled as 0. Connect node 0 to both nodes 1 and 2.
2. Second node is labeled as 1. Connect node 1 to node 2.
3. 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
         / \
         \_/

pro：给一个图，克隆

sol：

注意自环和给定的参数NULL情况，暂时不考虑重边

第一遍bfs，clone出所有的节点

第二遍将节点的孩子填充好
题目给的lable无重复，所以第一遍用map记录下

code：

/**
 * Definition for undirected graph.
 * struct UndirectedGraphNode {
 *     int label;
 *     vector<UndirectedGraphNode *> neighbors;
 *     UndirectedGraphNode(int x) : label(x) {};
 * };
 */
#include<iostream>
#include<stdio.h>
#include<set>
#include<string>
#include<map>
#include<vector>
#include<string.h>
#include<queue>
#define MAXN
using namespace std;


class Solution {
private:
    queue<UndirectedGraphNode*> myque;
    map<int, UndirectedGraphNode*> mymap, mymap2;
public:

    UndirectedGraphNode *cloneGraph(UndirectedGraphNode* node) {
        if (node == NULL) return NULL;
        while (!myque.empty())
            myque.pop();
        mymap.clear();
        int i, j, cnt;
        myque.push(node);
        UndirectedGraphNode *temp;
        while (!myque.empty()) {
            temp = myque.front();
            myque.pop();
            UndirectedGraphNode * newNode = new UndirectedGraphNode(temp->label);
            mymap[temp->label] = newNode;
            for (i = 0; i < temp->neighbors.size(); i++) {
                if (mymap.find(temp->neighbors[i]->label) == mymap.end())
                    myque.push(temp->neighbors[i]);
            }
        }

        UndirectedGraphNode *root, *newNode;
        mymap2.clear();
        myque.push(node);
        root = mymap[node->label];
        while (!myque.empty()) {
            temp = myque.front();
            myque.pop();
            newNode = mymap[temp->label];
            newNode->neighbors.clear();
            mymap2[newNode->label] = newNode;
            for (i = 0; i < temp->neighbors.size(); i++) {
                newNode->neighbors.push_back(mymap[temp->neighbors[i]->label]);
                if (mymap2.find(temp->neighbors[i]->label) == mymap2.end())
                    myque.push(temp->neighbors[i]);
            }
        }
        return root;
    }
};