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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. int main() {
  5. 	int n, k;
  6. 	cin>>n>>k;
  7. 	int dp[n+1][k+1]={};
  8. 	for(int i=1; i<=k; i++)
  9. 		dp[1][i]=1;
  10. 	for(int len=2; len<=n; len++){
  11. 		if(len%2==0){
  12. 			for(int i=1; i<=k; i++){
  13. 				for (int j=i+1; j<=k; j++){
  14. 					dp[len][i]+=dp[len-1][j];
  15. 				}
  16. 			}
  17. 		} else {
  18. 			for(int i=1; i<=k; i++){
  19. 				for(int j=1; j<=i-1; j++){
  20. 					dp[len][i]+=dp[len-1][j];
  21. 				}
  22. 			}
  23. 		}
  24. 	}
  25. 	int ans=0;
  26. 	for(int i=1; i<=k; i++)
  27. 		ans+=dp[n][i];
  28. 	if(n>1) ans*=2;
  29. 	cout<<ans<<endl;
  30. 	return 0;
  31. }
Success #stdin #stdout 0s 5300KB
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3 3
stdout
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10
https://ideone.com/gfOApR
language:
C++ (gcc 8.3)
created:
11 days ago
visibility:
public

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