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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 c=0;
  4. int rec(int n){
  5. 	c++;
  6.     if(n==1){
  7.     	return 1;
  8.     }else if(n==2){
  9.     	return 2;
  10.     }else{
  11.     	return -6*rec(n-1)-9*rec(n-2);
  12.     }
  13. }
  14.  
  15. int main(void) {
  16.     int n = 5;
  17.     printf("数列a%dの値は%d\n", n, rec(n));
  18.     printf("呼び出し回数は%dかいです。\n",c);
  19. 	return 0;
  20. }
  21.  
  22.  
Success #stdin #stdout 0s 5292KB
comments (?)
stdin 
Standard input is empty
stdout 
数列a5の値は-459
呼び出し回数は9かいです。
https://ideone.com/YQ9w1p
language:
C (gcc 8.3)
created:
15 days ago
visibility:
public

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