fork download 
  1. #include <stdio.h>
  2.  
  3. int func(int n) {
  4.     int a = 1, b = 2, c;
  5.     int i;
  6.  
  7.     if (n == 1) {
  8.         return a;
  9.     }
  10.     if (n == 2) {
  11.         return b;
  12.     }
  13.  
  14.     for (i = 3; i <= n; i++) {
  15.         c = 2 * a - 2 * b;
  16.         a = b;
  17.         b = c;
  18.     }
  19.  
  20.     return c;
  21. }
  22.  
  23. int main(void) {
  24.     int n = 3;
  25.     printf("数列anについて，n=%dのときの値は%d\n", n, func(n));
  26.     return 0;
  27. }
  28.  
Success #stdin #stdout 0s 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/MKTijo
language:
C (gcc 8.3)
created:
3 days 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!