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  1. #include <stdio.h>
  2. //練習問題G
  3.  
  4. int func(int n){
  5.     int a, b=2, c=1;
  6.     int i;
  7. if(n==1) return c;
  8. if(n==2) return b;
  9. for(i=3;i<=n;i++){
  10. 	a=-2*b+2*c;
  11. 	c=b;
  12. 	b=a;
  13. }
  14. 	return a;
  15. }
  16.  
  17.  
  18. int main(void) {
  19. 	int n = 5;
  20.     printf("数列anについて, n=%dのときの値は%d\n", n, func(n));
  21. 	return 0;
  22. }
  23.  
Success #stdin #stdout 0.01s 5296KB
comments (?)
stdin 
Standard input is empty
stdout 
数列anについて, n=5のときの値は-20
https://ideone.com/O8coP1
language:
C (gcc 8.3)
created:
14 days ago
visibility:
public

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