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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Name of the class has to be "Main" only if the class is public. */
  8. class Main
  9. {
  10. 	public static void main (String[] args) throws java.lang.Exception
  11. 	{
  12. 		// your code goes here
  13. 		Scanner sc = new Scanner(System.in);
  14. 		int n = sc.nextInt();
  15. 		int[] a = new int[n];
  16. 		for(int i=0;i<n;i++){
  17. 			a[i] = sc.nextInt();
  18. 		}
  19. 		if (n < 2) {
  20. 		    System.out.println(0);
  21. 		    return;
  22. 		}
  23.  
  24. 		int[][] dp = new int[n][2];
  25. 		int[][] pre = new int[n][2];
  26.  
  27.  
  28. 		dp[0][0] = Integer.MIN_VALUE;
  29. 		dp[0][1] = Integer.MIN_VALUE;
  30. 		dp[1][0] = a[0] + a[1];
  31. 		dp[1][1] = Integer.MIN_VALUE;
  32.  
  33. 		pre[0][0] = dp[0][0];
  34. 		pre[0][1] = dp[0][1];
  35. 		pre[1][0] = dp[1][0];
  36. 		pre[1][1] = dp[1][1];
  37.  
  38. 		int ans = dp[1][0];
  39.  
  40. 		for(int i=2;i<n;i++){
  41. 			int p1 = a[i] + a[i-1] + ((i-3>=0) ? dp[i-3][0] : 0);
  42. 			int p2 = a[i] + a[i-1];
  43. 			if(i-4>=0){
  44. 				p2 += Math.max(pre[i-4][0], pre[i-4][1]);
  45. 			}
  46. 			dp[i][0] = Math.max(p1, p2);
  47.  
  48. 			dp[i][1] = a[i] + a[i-1] + a[i-2];
  49. 			if(i-5 >= 0){
  50. 				dp[i][1] += Math.max(pre[i-5][0], pre[i-5][1]);
  51. 			}
  52.  
  53. 			pre[i][0] = Math.max(pre[i-1][0], dp[i][0]);
  54. 			pre[i][1] = Math.max(pre[i-1][1], dp[i][1]);
  55.  
  56. 			ans = Math.max(ans, Math.max(dp[i][0], dp[i][1]));
  57. 		}
  58. 		System.out.println(ans);
  59.  
  60. 	}
  61. }
Success #stdin #stdout 0.11s 54512KB
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https://ideone.com/lTTxeR
language:
Java (HotSpot 12)
created:
5 hours ago
visibility:
public

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