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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;
  4. int rec(int n){
  5.  c++;
  6.  if(n==1){
  7.   return 1;
  8.  }
  9.  else if (n==2){
  10.   return 2;
  11.  }
  12.  else{
  13.   return -6*rec(n-1) -9*rec(n-2);
  14.  }
  15. }
  16.  
  17. int main(void) {
  18.     int n = 5;
  19.  
  20.     printf("数列a%dの値は%d\n", n, rec(n));
  21.     printf("このときrecの呼び出し回数は%d\n",c);
  22.  return 0;
  23. }
Success #stdin #stdout 0.01s 5284KB
comments (?)
stdin 
Standard input is empty
stdout 
数列a5の値は-459
このときrecの呼び出し回数は9
https://ideone.com/aZFfBD
language:
C (gcc 8.3)
created:
72 days ago
visibility:
public

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