fork download
copy 
  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.  
  5. int rec(int n){
  6. 	c++;
  7. 	if (n == 1) {
  8.         return 1; 
  9.     }
  10.    else if (n == 2) {
  11.         return 2;
  12.     }
  13.     else{
  14.  
  15.     return -6*rec(n-1)-9*rec(n-2);
  16.     }
  17.  
  18. }
  19.  
  20. int main(void) {
  21.     int n = 5; 
  22.     int ans = rec(n);
  23.     printf("数列a%dの値は%d\n", n, ans);
  24.     printf("このときrecの呼び出し回数は%d\n", c);
  25. 	return 0;
  26. }
  27.  
  28.  
Success #stdin #stdout 0s 5320KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
数列a5の値は-459
このときrecの呼び出し回数は9
https://ideone.com/MsyScu
language:
C (gcc 8.3)
created:
18 hours ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!