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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.  	int a=rec(n);
  18.  	printf("数列a%dの値は%d\n",n,a);
  19.  	printf("この時recの呼び出し回数は%d",c);
  20.  	return 0;
  21.  }
  22.  
  23.  
Success #stdin #stdout 0s 5332KB
comments (?)
stdin 
Standard input is empty
stdout 
数列a5の値は-459
この時recの呼び出し回数は9
https://ideone.com/CZFOLx
language:
C (gcc 8.3)
created:
4 days ago
visibility:
public

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