Video solution | Intuition and Approach explained in detail | C++ | Backtracking
Video\nHello every one i have created a video solution for this problem and solved this video by developing intutition for backtracking (its in hindi), i am pre
# Video\nHello every one i have created a video solution for this problem and solved this video by developing intutition for backtracking (its in hindi), i am pretty sure you will never have to look for solution for this video ever again after watching this.\n\n\nThis video is the part of my playlist "Master backtracking".\nVideo Link: \n\nhttps://youtu.be/NcQzZLybnBs\n\n# Code\n```\nclass Solution {\npublic:\n\n    bool uniqueChar(string& str){\n        int store=0;\n        for(int i=0;i<str.size();i++){\n            int idxBit= str[i]-\'a\';\n            if((store & (1<<idxBit))>0){\n                return false;\n            }\n            store= store | (1<<idxBit);\n        }\n        return true;\n    }\n    int ans=0;\n    void helper(vector<string>& arr, int idx,vector<string>& temp){\n       //  ["ui", "qe"]\n        string str="";\n        for(int i=0;i<temp.size();i++){\n            str+= temp[i];\n        }\n        if(uniqueChar(str)){\n            int l=str.size();\n            ans=max(ans, l);\n        }\n\n\n        for(int i=idx;i<arr.size();i++){\n            temp.push_back(arr[i]);\n            if(uniqueChar(arr[i]))\n                helper(arr,i+1,temp);\n            temp.pop_back();\n        }\n\n    }\n    int maxLength(vector<string>& arr) {\n        vector<string> temp;\n        helper(arr, 0, temp);\n        return ans;\n        \n    }\n};\n```
['C++']