Leetcode-Graph-Hash

133. 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 #.

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     / \     \_/

#include <string>#include <iomanip>#include <utility> #include <memory>#include <iostream>#include <vector>#include <unordered_set>#include <unordered_map>#include <algorithm>using namespace std;struct UndirectedGraphNode {     int label;     vector<UndirectedGraphNode *> neighbors;     UndirectedGraphNode(int x) : label(x) {}; };typedef UndirectedGraphNode undgp;class Solution {public:    UndirectedGraphNode *cloneGraph(UndirectedGraphNode *node) {        if (!node)return node;        mmap.clear();        mset.clear();        innerv.clear();        innerv.reserve(1000000);        cloneGraph1(node);        if(mset.empty()){            decltype(node) res;            res = new UndirectedGraphNode(node->label);            return res;        }        unordered_map<undgp*, undgp*> mp1;        for (auto it : mset) {            mp1[it] = new undgp(it->label);        }        for (auto it : mset) {            auto dp = mp1[it];            for (auto it_ : it->neighbors) {                dp->neighbors.push_back(mp1[it_]);            }        }        return mp1[node];    }    void cloneGraph1(UndirectedGraphNode *node) {        if (!node || node->neighbors.empty())return;        auto resf = mmap.find(node);        mset.insert(node);        for (auto it : node->neighbors) {            resf = mmap.find(node);            mset.insert(it);            if (resf == mmap.end()) {                unordered_set<undgp*> tmps;                tmps.insert(it);                innerv.push_back(tmps);                mmap.insert(pair<undgp*,miter>(node, innerv.end()-1));                auto resf2 = mmap.find(it);                if (resf2 == mmap.end()) {                    unordered_set<undgp*> tmps2;                    tmps2.insert(node);                    innerv.push_back(tmps2);                    mmap.insert(pair<undgp*,miter>(it, innerv.end()-1));                } else {                    resf2->second->insert(node);                }                cloneGraph1(it);            } else {                auto resf1 = mmap[node]->find(it);                if (resf1 == mmap[node]->end()) {                    mmap[node]->insert(it);                    auto resf2 = mmap.find(it);                    if (resf2 == mmap.end()) {                        unordered_set<undgp*> tmps2;                        tmps2.insert(node);                        innerv.push_back(tmps2);                        mmap.insert(pair<undgp*,miter>(it, innerv.end()-1));                    } else {                        resf2->second->insert(node);                    }                    cloneGraph1(it);                }            }        }// it    }    vector<unordered_set<undgp*>> innerv;    typedef vector<unordered_set<undgp*>>::iterator miter;    unordered_map<undgp*,decltype(innerv)::iterator> mmap;    unordered_set<undgp*> mset;};int main() {    Solution s;    UndirectedGraphNode *d = new UndirectedGraphNode(12);    auto d1 =  s.cloneGraph(d);    cout << d1->label << endl;    delete d1;    delete d;    return 0;}