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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define int long long
  4.  
  5. int ans[500005];
  6.  
  7. void precomp(){
  8. 	for(int i = 2; i <= 500000; i++)ans[i] = 1e13;
  9. 	// precomp divisor
  10. 	vector<int> div[500005];
  11. 	for (int i = 3; i <= 500000; i++) {
  12. 		int temp = i;
  13. 		while(true) {
  14. 			temp += i;
  15. 			if (temp <= 500000) div[temp].push_back(i);
  16. 			else break;
  17. 		}
  18. 	}
  19.  
  20. 	ans[1] = 1;
  21. 	for(int i = 2; i <= 500000; i++){
  22. 		if(i%2==0) continue;
  23. 		if(i>2)ans[i] = min(ans[i], ans[i-2]+1);
  24. 		for (auto& j : div[i]) {
  25. 			ans[i] = min(ans[i], ans[j-2] + ans[i/j]);
  26. 		}
  27. 	}
  28.  
  29. 	for(int i = 2; i <= 500000; i++)ans[i] = (ans[i] == 1e13? -1:ans[i]);
  30. }
  31.  
  32. void fun(){
  33. 	int m;
  34. 	cin >> m;
  35. 	cout << ans[m] << '\n';
  36. }
  37.  
  38. main() {
  39. 	precomp();
  40. 	int t; cin >> t;
  41. 	while(t--)fun();
  42. }
Success #stdin #stdout 0.54s 88864KB
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https://ideone.com/v6lTYi
language:
C++14 (gcc 8.3)
created:
4 days ago
visibility:
public

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