C++||Hash map||Easy to Understand
```\nclass Solution {\npublic:\n    bool canFormArray(vector& arr, vector>& pieces) \n    {\n        vector ps(101,-1);\n        for(int i=0;i<pieces.size();i++
```\nclass Solution {\npublic:\n    bool canFormArray(vector<int>& arr, vector<vector<int>>& pieces) \n    {\n        vector<int> ps(101,-1);\n        for(int i=0;i<pieces.size();i++)\n        {\n            ps[pieces[i][0]]=i;\n        }\n        for(int i=0;i<arr.size();)\n        {\n            int p=ps[arr[i]];\n            if(p==-1)\n            {\n                return false;\n            }\n            for(int j=0;j<pieces[p].size();j++)\n            {\n                if(pieces[p][j]!=arr[i++])\n                    return false;\n            }\n        }\n        return true;\n        \n    }\n};\n//if you like the solution plz upvote.
['C']