3300 - 找规律(斐波那契数列)
时间限制 : 1 秒
内存限制 : 128 MB
<span style="font-family:宋体;">【问题描述】</span>
<span style="font-family:宋体;">找规律:根据下列规律找出第</span><span>N</span><span style="font-family:宋体;">个数是多少?</span><span> 1,2,3,5</span><span style="font-family:宋体;">……(</span><span>3<=n<=20</span><span style="font-family:宋体;">)</span>
<span></span>
<span style="font-family:宋体;">【输入格式】</span>
<span style="font-family:宋体;">一个正数数</span><span>n</span><span style="font-family:宋体;">(</span><span>3<=n<=20</span><span style="font-family:宋体;">)</span>
<span style="font-family:宋体;">【输出格式】</span>
<span style="font-family:宋体;">输出一个正整数</span><span> </span>
<span style="font-family:宋体;">【输入样例】</span>
<span>5</span>
<span style="font-family:宋体;">【输出样例】</span>
<span>8</span>
<span style="font-family:宋体;">【数据规模】</span>
<span>3<=n<=20</span>
<span style="font-family:宋体;">【时间限制】</span>
<span>1s</span>
题目输入
题目输出
输入/输出样例
输入格式
输出格式
C++解答
#include<iostream> using namespace std; int a[1000]; int main() { int n; cin>>n; a[1]=1; a[2]=2; for(int i=3;i<=n;++i) a[i]=a[i-1]+a[i-2]; cout<<a[n]; }