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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.  if(n==1){
  6.  	return 1+c++;
  7.  }
  8.  else if(n==2){
  9.  	return 2+c++;
  10.  }
  11.  else{
  12.  	return -6*rec(n-1)-9*rec(n-2)+c++;
  13.  }
  14. }
  15.  
  16. int main(void) {
  17.     int n = 5;
  18.     printf("数列a%dの値は%d\nこのときrecの呼び出し回数は%d", n, rec(n),c);
  19. 	return 0;
  20. }
  21.  
  22.  
Success #stdin #stdout 0s 5324KB
comments (?)
stdin 
Standard input is empty
stdout 
数列a5の値は128
このときrecの呼び出し回数は0
https://ideone.com/rbEzSA
language:
C (gcc 8.3)
created:
1 day ago
visibility:
public

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