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  1. #include <array>
  2. #include <utility>
  3. #include <iostream>
  4. #include <algorithm>
  5. #include <unordered_map>
  6. using type_key = unsigned long long;
  7. using type_value = std::array<std::pair<unsigned int, unsigned int>, 5>;
  8. size_t value_valid_size(type_value &values) {
  9.     size_t i, size = values.size();
  10.     for (i = 0; i < size && values[i].first; i++);
  11.     return i;
  12. }
  13. void value_inspect(type_value &values) {
  14.     std::cout << "[";
  15.     for (size_t i = 0; i < values.size(); i++) {
  16.         if (0 < i) std::cout << ", ";
  17.         std::cout << "[" << values[i].first << ", " << values[i].second << "]";
  18.     }
  19.     std::cout << "]";
  20. }
  21. type_value &value_append(type_value &values, type_value::value_type value) {
  22.     size_t cap = values.size(), size = value_valid_size(values);
  23.     if (size < cap)
  24.         values[size] = value;
  25.     else
  26.         fprintf(stderr, "values.size(): %u, required: %u\n", cap, cap + 1), exit(EXIT_FAILURE);
  27.     return values;
  28. }
  29. type_value &operator<<(type_value &values, type_value::value_type value) {
  30.     return value_append(values, value);
  31. }
  32. type_value f(unsigned int m) {
  33.     std::unordered_map<type_key, type_value> map(1 << 24);
  34.     for (type_key a = 1; ; a++) {
  35.         for (type_key b = 1; b < a; b++) {
  36.             type_key c = a * a * a - b * b * b;
  37.             if (value_valid_size(value_append(map[c], {a, b})) == m) return map[c];
  38.         }
  39.     }
  40.     return {{}};
  41. }
  42. int main() {
  43.     type_value v = f(5);
  44.     value_inspect(v);
  45.     return 0;
  46. }
  47.  
Success #stdin #stdout 4.18s 845472KB
comments (?)
stdin 
Standard input is empty
stdout 
[[1134, 357], [1155, 504], [1246, 805], [2115, 2004], [4746, 4725]]
https://ideone.com/teo5Mm
language:
C++14 (clang 8.0)
created:
79 days ago
visibility:
secret

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