迭代算法实现斐波那契数列

#include
int main()
{
  int a=1;
  int b=1;
  int c=1;
  int d=0;
  int line=0;
  scanf("%d",&d);
  while(line<=d-3)
  {
    line++;
    c=a+b;
    a=b;
    b=c;
  }
  printf("%d",c);
  return 0;
}