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  1. import java.util.ArrayList;
  2. import java.util.List;
  3. import java.util.Scanner;
  4.  
  5. class A_NoldbachProblem {
  6. 	public static void main(String[] args) throws Exception {
  7. 		Scanner scan = new Scanner(System.in);
  8. 		int n = scan.nextInt();
  9. 		int k = scan.nextInt()-1;
  10. 		PrimeGen p = new PrimeGen(n);
  11. 		List<Integer> prims = new ArrayList<Integer>();
  12. 		for(int i = 2; i <= n; i++){
  13. 			if(p.isPrime(i)>0){
  14. 				prims.add(i);
  15. 			}
  16. 		}
  17. 		int sum = 0;
  18. 		for(int i = 0; i < prims.size() - 1; i++){
  19. 			int c = prims.get(i) + prims.get(i+1) + 1;
  20. 			if(c <= n && p.isPrime(c)>0){
  21. 				sum ++;
  22. 			}
  23. 		}
  24. 		System.out.println(sum>=k?"YES":"NO");
  25. 	}
  26.  
  27. 	static int sum(List<Integer> is) {
  28. 		int c = 0;
  29. 		for (int i : is)
  30. 			c += i;
  31. 		return c;
  32. 	}
  33.  
  34. 	static class PrimeGen {
  35. 		public PrimeGen(int m) {
  36. 			m = (int) Math.sqrt(m);
  37. 			double max = 0;
  38. 			int r = 1;
  39. 			for (int i = 0; i < 4;) {
  40. 				max += r * m / Math.pow(Math.log1p(m), ++i);
  41. 				r *= i;
  42. 			}
  43. 			p = new int[(int) max];
  44. 			for (int i = 0, e = 2; i < p.length; i++) {
  45. 				for (; isPrime(e) < 1; e++)
  46. 					;
  47. 				p[i] = e++;
  48. 			}
  49. 			this.m = p[p.length - 1];
  50. 			this.m = this.m * this.m;
  51. 		}
  52.  
  53. 		int isPrime(int n) {
  54. 			for (int e : p)
  55. 				if (e < 1)
  56. 					break;
  57. 				else if (n != e && n % e < 1)
  58. 					return 0;
  59. 			return 1;
  60. 		}
  61.  
  62. 		int max() {
  63. 			return m;
  64. 		}
  65.  
  66. 		int[] p;
  67. 		int m;
  68. 	}
  69. }
  70.  
Success #stdin #stdout 0.06s 213824KB
comments (?)
stdin 
27 2
stdout 
YES
https://ideone.com/gCcpU
language:
Java (HotSpot 12)
created:
15 years ago
visibility:
secret

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