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  1. #include <stdio.h>
  2. //a{n} = -6a{n-1} -9a{n-2}, a{1}=1, a{2}=2(再帰あり版)
  3. int rec(int n){
  4. 	if(n==1){
  5. 		return 1;
  6. 	}
  7. 	else if(n==2){
  8. 		return 2;
  9. 	}
  10. 	else{
  11. 		return -6*rec(n-1)-9*rec(n-2);
  12. 	}
  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 0s 5288KB
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Standard input is empty
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数列a4の値は108
https://ideone.com/R9DskW
language:
C (gcc 8.3)
created:
8 days ago
visibility:
public

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