多种方法
import java.util.*;
public class Solution {
// 递归
public int Fibonacci2(int n) {
if (n < 2) {
return n;
} else {
return Fibonacci(n - 1) + Fibonacci(n - 2);
}
}
// 动态规划
public int Fibonacci1(int n) {
if (n < 2) {
return n;
} else {
int[] a = new int[n + 1];
a[0] = 0;
a[1] = 1;
for (int i = 2; i <= n; i++) {
a[i] = a[i - 1] + a[i - 2];
}
return a[n];
}
}
// 最优方法：迭代
public int Fibonacci(int n) {
if (n < 2) {
return n;
} else {
int pre = 1;
int pre_pre = 0;
int sum = 0;
for (int i = 2; i <= n; i++) {
sum = pre + pre_pre;
pre_pre = pre;
pre = sum;
}
return sum;
}
}
public static void main(String[] args) {
Solution s = new Solution();
int intArray[][] = {{1, 2}};
String str = "We Are Happy";
int n = 2;
int ans = s.Fibonacci(n);
System.out.println(ans);
}
}
