第0项是0
第1项是1
……………..
f(n)=f(n-1)+f(n-2)
0,1, 1, 2, 3, 5, 8, 13, 21, n+)-134, 55, 89, 144, 233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368……..
按照上面这种形式进行递推
递归写法
long long Fibonacci(unsigned int n)
{
if (n == 0)
return 0;
if (n == 1)
return 1;
return Fibonacci(n - 1) + Fibonacci(n - 2);
}
递推写法
long long Fibonacci(unsigned int n){
int result[2]={0,1};
if (n < 2){
return result[n];
}
int prev = 0;
int cur = 1;
for (int i = 2; i <= n; i++){
int temp = cur;
cur = prev + cur;
prev = temp;
}
return cur;
}
0 1 1 2 3
prev cur
prev cur
上面个cur要更新,但是还要保留给prev因此将cur保存到temp,然后赋值给prev
一直在往前滑动一个单位