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  1. #include <stdio.h>
  2.  
  3. void fr(int n, int a[])
  4. {
  5.   int tmp;
  6.  
  7.   if (n == 0)
  8.     return;
  9.  
  10.   tmp = a[0] * a[2] + 1;
  11.   a[2] = a[1];
  12.   a[1] = a[0];
  13.   a[0] = tmp;
  14.  
  15.   fr(n - 1, a);
  16. }
  17.  
  18. int f(int n)
  19. {
  20.   int a[3] = { 1, 1, 1 };
  21.  
  22.   if (n <= 2)
  23.     return 1;
  24.  
  25.   fr(n - 2, a);
  26.  
  27.   return a[0];
  28. }
  29.  
  30. int main(void)
  31. {
  32.   int k;
  33.   for (k = 0; k < 10; k++)
  34.     printf("f(%d) = %d\n", k, f(k));
  35.   return 0;
  36. }
  37.  
Success #stdin #stdout 0s 1832KB
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stdin
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Standard input is empty
stdout
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f(0) = 1
f(1) = 1
f(2) = 1
f(3) = 2
f(4) = 3
f(5) = 4
f(6) = 9
f(7) = 28
f(8) = 113
f(9) = 1018
https://ideone.com/mBiqnM
language:
C99 (gcc 8.3)
created:
11 years ago
visibility:
public

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