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  1. #include <vector>
  2. #include <algorithm>
  3. #include <cstdlib>
  4. #include <iostream>
  5.  
  6. template<class bidiiter>
  7. bidiiter random_unique(bidiiter begin, bidiiter end, size_t num_random) {
  8. size_t left = std::distance(begin, end);
  9. while (num_random--) {
  10. bidiiter r = begin;
  11. std::advance(r, rand()%left);
  12. std::swap(*begin, *r);
  13. ++begin;
  14. --left;
  15. }
  16. return begin;
  17. }
  18.  
  19. int main() {
  20. std::vector<int> a(10000);
  21. for(int i=0; i<10000; ++i)
  22. a[i] = i;
  23. random_unique(a.begin(), a.end(), 13);
  24. for(int i=0; i<25; ++i) {
  25. std::cout << a[i] << '\n';
  26. }
  27. return 0;
  28. }
Success #stdin #stdout 0.01s 5476KB
stdin
Standard input is empty
stdout
9383
5588
9183
1463
1209
565
7578
6136
4249
3069
8592
7205
9862
13
14
15
16
17
18
19
20
21
22
23
24