Fibonacci数列

Fibonacci数列

#include <iostream>

#include <ctime>

 

int fibonacci(int n) {

    if (n <= 1) return 1;

    return fibonacci(n-1)+fibonacci(n-2);

 

}

int Fibonacci(int lN,int lA=1,int lB=1)

{

    if (lN==2||lN==1)

    {

        return lB;

    }

 

    return Fibonacci(lN-1,lB,lA+lB);

}

void runTime(int i) {

    clock_t start, finish;

    start = std::clock();

    fibonacci(i);

    finish = std::clock();

    std::cout << i << ":" << (finish - start)/1000 << "ms" << std::endl;

    start = std::clock();

    Fibonacci(i);

    finish = std::clock();

    std::cout << "尾递归:" << i << ":" << (finish - start)/1000 << "ms" << std::endl;

}

 

int main() {

    runTime(45);

    runTime(46);

    runTime(47);

    return 0;