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  1. #include <stdio.h>
  2.  
  3. int func(int n){
  4.     int a, b = 2, c = 1;
  5.     int i;
  6.     if(n==1)
  7.    {
  8.    	return 1;
  9.    }
  10.    else if(n==2)
  11.    {
  12.    	return 2;
  13.    }
  14.     else
  15.  
  16.     { for(i = 2; i < n; i++) 
  17.     {
  18.         a = -2 * b + 2 * c;
  19.         c = b;
  20.         b = a;
  21.     }
  22.  
  23.     }
  24.     return a;
  25. }
  26.  
  27. int main(void) {
  28.     int n = 3;
  29.     printf("数列anについて, n=%dのときの値は%d\n", n, func(n));
  30.     return 0;
  31. }
  32.  
Success #stdin #stdout 0.01s 5320KB
comments (?)
stdin 
Standard input is empty
stdout 
数列anについて, n=3のときの値は-2
https://ideone.com/3xdFkk
language:
C (gcc 8.3)
created:
12 days ago
visibility:
public

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