给定一个数字K ,任务是打印出现在斐波那契二叉树第 K层的斐波那契数字。
例子:
Input: K = 3
Output: 2, 3, 5, 8
Explanation:
Fibonacci Binary Tree for 3 levels:
0
/ \
1 1
/\ / \
2 3 5 8
Numbers present at level 3: 2, 3, 5, 8
Input: K = 2
Output: 1, 1
Explanation:
Fibonacci Binary Tree for 2 levels:
0
/ \
1 1
Numbers present at level 2: 1, 1
朴素的方法:朴素的方法是构建一个斐波那契二叉树(斐波那契数的二叉树),然后获取特定级别 K 的元素。
但是,这种方法对于大数字已经过时了,因为它需要太多时间。
有效的方法:由于可以通过查找范围[2 K – 1 , 2 K – 1] 中的元素来找到将出现在树的某个任意级别 K 中的元素。所以:
- 使用动态规划找到最多 10 6的斐波那契数并将它们存储在一个数组中。
- 计算水平的 left_index 和 right_index 为:
left_index = 2K - 1 right_index = 2K - 1
- 从斐波那契数组的 left_index 到 right_index 打印斐波那契数列。
下面是上述方法的实现:
C++
// C++ program to print the Fibonacci numbers
// present at K-th level of a Binary Tree
#include
using namespace std;
// Initializing the max value
#define MAX_SIZE 100005
// Array to store all the
// fibonacci numbers
int fib[MAX_SIZE + 1];
// Function to generate fibonacci numbers
// using Dynamic Programming
void fibonacci()
{
int i;
// 0th and 1st number of the series
// are 0 and 1
fib[0] = 0;
fib[1] = 1;
for (i = 2; i <= MAX_SIZE; i++) {
// Add the previous two numbers in the
// series and store it
fib[i] = fib[i - 1] + fib[i - 2];
}
}
// Function to print the Fibonacci numbers
// present at Kth level of a Binary Tree
void printLevel(int level)
{
// Finding the left and right index
int left_index = pow(2, level - 1);
int right_index = pow(2, level) - 1;
// Iterating and printing the numbers
for (int i = left_index;
i <= right_index; i++) {
cout << fib[i - 1] << " ";
}
cout << endl;
}
// Driver code
int main()
{
// Precomputing Fibonacci numbers
fibonacci();
int K = 4;
printLevel(K);
return 0;
}
Java
// Java program to print the Fibonacci numbers
// present at K-th level of a Binary Tree
import java.util.*;
class GFG{
// Initializing the max value
static final int MAX_SIZE = 100005;
// Array to store all the
// fibonacci numbers
static int []fib = new int[MAX_SIZE + 1];
// Function to generate fibonacci numbers
// using Dynamic Programming
static void fibonacci()
{
int i;
// 0th and 1st number of the series
// are 0 and 1
fib[0] = 0;
fib[1] = 1;
for (i = 2; i <= MAX_SIZE; i++) {
// Add the previous two numbers in the
// series and store it
fib[i] = fib[i - 1] + fib[i - 2];
}
}
// Function to print the Fibonacci numbers
// present at Kth level of a Binary Tree
static void printLevel(int level)
{
// Finding the left and right index
int left_index = (int) Math.pow(2, level - 1);
int right_index = (int) (Math.pow(2, level) - 1);
// Iterating and printing the numbers
for (int i = left_index;
i <= right_index; i++) {
System.out.print(fib[i - 1]+ " ");
}
System.out.println();
}
// Driver code
public static void main(String[] args)
{
// Precomputing Fibonacci numbers
fibonacci();
int K = 4;
printLevel(K);
}
}
// This code is contributed by Rajput-Ji
Python3
# Python program to print the Fibonacci numbers
# present at K-th level of a Binary Tree
# Initializing the max value
MAX_SIZE = 100005
# Array to store all the
# fibonacci numbers
fib =[0]*(MAX_SIZE + 1)
# Function to generate fibonacci numbers
# using Dynamic Programming
def fibonacci():
# 0th and 1st number of the series
# are 0 and 1
fib[0] = 0
fib[1] = 1
for i in range(2, MAX_SIZE + 1):
# Add the previous two numbers in the
# series and store it
fib[i] = fib[i - 1] + fib[i - 2]
# Function to print the Fibonacci numbers
# present at Kth level of a Binary Tree
def printLevel(level):
# Finding the left and right index
left_index = pow(2, level - 1)
right_index = pow(2, level) - 1
# Iterating and printing the numbers
for i in range(left_index, right_index+1):
print(fib[i - 1],end=" ")
print()
# Driver code
# Precomputing Fibonacci numbers
fibonacci()
K = 4
printLevel(K)
# This code is contributed by shivanisinghss2110
C#
// C# program to print the Fibonacci numbers
// present at K-th level of a Binary Tree
using System;
class GFG{
// Initializing the max value
static int MAX_SIZE = 100005;
// Array to store all the
// fibonacci numbers
static int []fib = new int[MAX_SIZE + 1];
// Function to generate fibonacci numbers
// using Dynamic Programming
static void fibonacci()
{
int i;
// 0th and 1st number of the series
// are 0 and 1
fib[0] = 0;
fib[1] = 1;
for (i = 2; i <= MAX_SIZE; i++) {
// Add the previous two numbers in the
// series and store it
fib[i] = fib[i - 1] + fib[i - 2];
}
}
// Function to print the Fibonacci numbers
// present at Kth level of a Binary Tree
static void printLevel(int level)
{
// Finding the left and right index
int left_index = (int) Math.Pow(2, level - 1);
int right_index = (int) (Math.Pow(2, level) - 1);
// Iterating and printing the numbers
for (int i = left_index;
i <= right_index; i++) {
Console.Write(fib[i - 1]+ " ");
}
Console.WriteLine();
}
// Driver code
public static void Main(string[] args)
{
// Precomputing Fibonacci numbers
fibonacci();
int K = 4;
printLevel(K);
}
}
// This code is contributed by Yash_R
Javascript
输出:
13 21 34 55 89 144 233 377
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