fork download
copy 
  1. #include <bits/stdc++.h>
  2. #define int long long
  3.  
  4. using namespace std;
  5.  
  6. const int MOD = 998244353;
  7. vector<int> prime((int)1e6 + 1, 1);
  8. void solve(){
  9. 	int n, m;
  10. 	cin >> n >> m;
  11.  
  12. 	auto bin = [&](int a, int b, auto && self) -> int {
  13. 		a %= MOD;
  14. 		if(b == 0)return 1;
  15. 		int g = self(a, b / 2, self);
  16. 		g *= g;
  17. 		g %= MOD;
  18. 		if(b % 2)g *= a;
  19. 		g %= MOD;
  20. 		return g;
  21. 	};
  22.  
  23. 	int ans = 0;
  24. 	int prev = 1;
  25. 	for(int i = 1; i <= n; i++){
  26. 		ans += bin(m, i, bin);
  27. 		ans %= MOD;
  28. 	}
  29. 	int cur = 1;
  30. 	for(int i = 1; i <= n; i++){
  31. 		if(prime[i]){
  32. 			cur *= i;
  33. 			if(cur > m)break;
  34. 		}
  35.  
  36. 		int g = m / cur;
  37. 		g %= MOD;
  38. 		prev *= g;
  39. 		prev %= MOD;
  40. 		ans -= prev;
  41. 		if(ans < 0)ans += MOD;
  42. 		ans %= MOD;
  43.  
  44. 	}
  45.  
  46. 	cout << ans << "\n";
  47. }
  48.  
  49. int32_t main(){
  50. 	ios_base::sync_with_stdio(false);
  51. 	cin.tie(nullptr);
  52.  
  53. 	int t = 1;
  54. 	// cin >> t;
  55.  
  56. 	for(int i = 2; i <= 1e6; i++){
  57. 		if(!prime[i])continue;
  58. 		for(int j = i * i; j <= 1e6;  j += i)prime[j] = 0;
  59. 	}
  60.  
  61. 	for(int i = 1; i <= t; i++){
  62. 		solve();
  63. 	}
  64. 	return 0;
  65. }
Success #stdin #stdout 0.02s 10964KB
comments (?)
stdin
copy 
4 2
stdout
copy 
26
https://ideone.com/gleN6x
language:
C++14 (gcc 8.3)
created:
9 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!