/*
*Definition:
*Author:
*Date:
*/
#include <iostream>
#include <array>
#include<vector>
using namespace std;
class Fibo{
int m_num=0;
const int m_firstNum = 0;
const int m_secondNum = 1;
vector<int>m_fib;
public:
Fibo(){
}
Fibo(int n) :m_num(n)
{
int temp1 = m_firstNum;
m_fib.push_back(temp1);
int temp2 = m_secondNum;
m_fib.push_back(temp2);
int sum;
for (int i = 2; i < n; i++)
{
sum = temp1 + temp2;
m_fib.push_back(sum);
}
}
//高效法，复杂度为N
int getFibo(int &num){
if (num == 0){
return 0;
}
else if (num == 1)
{
return 1;
}
else if (num > 1)
{
int sum;
int Ftemp = m_firstNum;
int Stemp = m_secondNum;
for (int i = 0; i < num - 2; i++)
{
sum = Ftemp + Stemp;
Ftemp = Stemp;
Stemp = sum;
}
return sum;
}
else
{
cout << "Please input the right positive number." << endl;
}
}
//递归法，复杂度为2ˇn,效率慢
int getFiboDigui(int &num)
{
if (num<2)
{
cout << "Please input the number bigger than 2" << endl;
return 0;
}
int Finnum;
Finnum = this->m_fib[num - 2] + this->m_fib[num - 1];
return Finnum;
}
};
int main()
{
Fibo f;
Fibo f2(5);
int pos;
cout << "Input the position you want to know: " << endl;
cin >> pos;
cout << "The number:" << f.getFibo(pos) << endl;
cout << "The 2number:" << f2.getFiboDigui(pos) << endl;
system("PAUSE");
return 0;
}
递归法时间复杂度为
高效：
