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  1. #include <stdio.h>
  2. int c;
  3. // a(n) = 2*a(n-1) + a(n-2), a1=2, a2=3
  4. int rec(int n) {
  5. 		c++;
  6.     if (n == 1) return 2;
  7.     if (n == 2) return 3;
  8.     return 2 * rec(n - 1) + rec(n - 2);
  9. }
  10.  
  11. int main(void) {
  12.     int n;
  13.     scanf("%d", &n);
  14.     printf("数列a%dの値は%d\n", n, rec(n));
  15. 	printf("recは%d回呼び出し\n",c);
  16.     return 0;
  17. }
  18.  
  19.  
Success #stdin #stdout 0.01s 5284KB
comments (?)
stdin 
4
stdout 
数列a4の値は19
recは5回呼び出し
https://ideone.com/BPU8nW
language:
C (gcc 8.3)
created:
1 day ago
visibility:
public

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