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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.  
  7.     if (n == 1) {
  8.         return 1;
  9.     } 
  10.     else if (n == 2) {
  11.         return 2;
  12.     } 
  13.     else {
  14.         return -6*rec(n-1)-9*rec(n-2);
  15.     }
  16.  
  17. }
  18.  
  19. int main(void) {
  20.     int n = 5;
  21.     printf("数列a%dの値は%d\n", n, rec(n));
  22.     printf("このときrecの呼び出し回数は%d\n",c);
  23. 	return 0;
  24. }
  25.  
  26.  
Success #stdin #stdout 0s 5284KB
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Standard input is empty
stdout
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数列a5の値は-459
このときrecの呼び出し回数は9
https://ideone.com/r2Da72
language:
C (gcc 8.3)
created:
1 day ago
visibility:
public

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