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  1. #include <iostream>
  2. #include <map>
  3. #include <vector>
  4.  
  5. std::map<int, std::vector<int>> foo(std::map<int, int> m)
  6. {
  7.     std::map<int, std::vector<int>> res;
  8.  
  9.     while (!m.empty())
  10.     {
  11.         auto it = m.begin();
  12.         const auto key = it->first;
  13.         auto& v = res[key];
  14.  
  15.         while (it != m.end()) {
  16.             auto value = it->second;
  17.             v.push_back(value);
  18.             m.erase(it);
  19.             it = m.find(value);
  20.         }
  21.     }
  22.     return res;
  23. }
  24.  
  25. int main()
  26. {
  27.     std::map<int, int> my_map = { {2, 31}, {4, 36}, {5, 29}, {6, 24}, {24, 49},
  28.                                   {25, 83}, {29, 63}, {36, 42}, {42, 79} };
  29.  
  30.     auto res = foo(my_map);
  31.  
  32.     for (const auto& p : res) {
  33.         std::cout << p.first << ":";
  34.         for (const auto& e : p.second) {
  35.             std::cout << e << " ";
  36.         }
  37.         std::cout << std::endl;
  38.     }
  39. }
  40.  
Success #stdin #stdout 0s 15240KB
comments ()
stdin
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Standard input is empty
stdout
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2:31 
4:36 42 79 
5:29 63 
6:24 49 
25:83
https://ideone.com/sCukmR
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

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