斐波拉契数列 优化
#include <iostream>using namespace std;long a[1000];//斐波拉契数列long fib(int n){ if(n<=1) return n; if(a[n]!=0)return a[n];//将已经计算过得值存放起来 return a[n] = fib(n-1)+fib(n-2);}int main(){ cout << fib(50) << endl; return 0;}