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  1. #include <iostream>
  2. #include <memory>
  3. #include <numeric>
  4. #include <random>
  5. #include <unordered_map>
  6.  
  7. int main() {
  8.   constexpr std::size_t min = 12345;
  9.   constexpr std::size_t max = 87654321;
  10.   constexpr std::size_t size = 8;
  11.  
  12.   std::random_device device;
  13.   std::mt19937 engine{device()};
  14.   std::unique_ptr<std::size_t[]> array{new std::size_t[size]};
  15.   std::unordered_map<std::size_t, std::size_t> map;
  16.  
  17.   map.reserve(max - min - size + 1);
  18.   std::iota(array.get(), array.get() + size, min);
  19.  
  20.   for (std::size_t i = 0; i != size; ++i) {
  21.     std::uniform_int_distribution<std::size_t> dist{i, max - min};
  22.     auto index = dist(engine);
  23.     std::swap(array[i], index < size
  24.                             ? array[index]
  25.                             : map.insert({index, min + index}).first->second);
  26.   }
  27.  
  28.   if (size != 0) {
  29.     std::cout << array[0];
  30.     for (size_t i = 1; i != size; ++i) std::cout << ", " << array[i];
  31.     std::cout << "\n";
  32.   }
  33. }
  34.  
Success #stdin #stdout 0.55s 3276KB
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Standard input is empty
stdout
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31604388, 16498194, 37456527, 10150801, 8115387, 32787686, 776314, 2529923
https://ideone.com/CAwuxW
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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