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  1. #include <stdio.h>
  2. //a{n} = 2a{n-1} + a{n-2}, a{1}=2, a{2}=3(再帰なし版)
  3.  
  4. int rec(int n){
  5. 	if(n==1){
  6. 		return 2;
  7. 	}
  8. 	else if(n==2){
  9. 		return 3;
  10. 	}
  11. 	else{
  12. 		return 2*rec(n-1)+rec(n-2);
  13. 	}
  14. }
  15. int main(void) {
  16.     int n = 4;
  17.     printf("数列a%dの値は%d\n", n, rec(n));
  18. 	return 0;
  19. }
  20.  
  21.  
Success #stdin #stdout 0.01s 5308KB
comments (?)
stdin 
Standard input is empty
stdout 
数列a4の値は19
https://ideone.com/aTJ1Fp
language:
C (gcc 8.3)
created:
4 days ago
visibility:
public

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