Simple and Short solution | O(nlogn) | only 1 map | readable code
Just did as told in the Question\nIf you understood the solution please upvote it. Thank you\nclass NumberContainers {\npublic:\n    map< int, int> mp;\n    \n 
Just did as told in the Question\nIf you understood the solution please upvote it. Thank you\n```class NumberContainers {\npublic:\n    map< int, int> mp;\n    \n    NumberContainers() {}\n    \n    void change(int index, int number) {\n        mp[index]=number;\n    }\n    \n    int find(int number) {\n       for(auto it : mp){\n           if(it.second==number){\n               return it.first;\n           }\n       }\n        return -1;\n    }\n};\n\t```
['C']