Making File Names Unique LeetCode solution in C++

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class Solution {
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 public:
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  vector<string> getFolderNames(vector<string> &names) {
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    // You can understand the code by seeing explanation below
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    unordered_map<string, int> mp;
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    vector<string> res;
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    for (auto i : names) {
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      string val = i;
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      int cnt = mp[val];
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      while (mp[val] != 0) {
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        val = i + '(' + to_string(cnt) + ')';
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        cnt++;
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        mp[i] = cnt;
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      }
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      mp[val]++;
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      res.emplace_back(val);
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    }
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    return res;
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    // For better Understanding Code explained Line by line
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    // names = ["d", "d(1)", "d(2)", "d"]
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    // running for loop
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    // val = "d";
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    // cnt = mp[val] = mp["d"] = 0;
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    // mp[val] = 0, so while loop not executed
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    // mp[val]++ -> mp["d"] = 0+1 = 1;
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    // res = ["d"]
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    // Same for "d(1)"
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    // mp["d(1)"] = 0+1 = 1;
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    // res = ["d", "d(1)"]
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    // Same for "d(2)"
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    // mp["d(2)"] = 0+1 = 1;
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    // res = ["d", "d(1)", "d(2)"]
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    // now, i = "d", val = "d";
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    // cnt = mp[val] = mp["d"] = 1, (appeared before)
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    // while loop executed bcoz mp[val] = 1 which is greater than 0
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    // In while loop,
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    // cnt = 1+1 = 2;
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    // val = i + '(' + to_string(cnt) + ')' = "d(2)"
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    // mp[i] = mp["d"] = cnt = 2;
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    // now mp[val] = mp["d(2)"] = 1, (appeared before)
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    // while loop executed bcoz mp[val] = 1 which is greater than 0
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    // In while loop,
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    // cnt = 2+1 = 3;
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    // val = i + '(' + to_string(cnt) + ')' = "d(3)"
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    // mp[i] = mp["d"] = cnt = 3;
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    // now mp[val] = mp["d(3)"] = 0
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    // while loop closed
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    // mp[val]++ = mp["d(3)"] = 0+1 = 1;
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    // res = ["d", "d(1)", "d(2)", "d(3)"]
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    // now, return res;
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  }
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};