使用Stack以降序打印给定整数的质数因子

给定整数N ，任务是使用堆栈数据结构以降序打印N的素因数。

例子：

Input: N = 34
Output:
17 2
Explanation:
The prime factors of the number 34 is 2 and 17.

Input: N = 8
Output: 2

方法：想法是使用Stack数据结构存储N的所有素数，最后打印出Stack中的所有值。请按照以下步骤解决问题：

1. 初始化堆栈，说st 。
2. 在N！= 1时运行循环。从i = 2开始，对于i的每个值，循环运行直到N％i == 0并将i推入堆栈st并将N更新为N / i。
3. 最后，从堆栈st的顶部到底部打印所有值。

下面是上述方法的实现：

C++

// C++ program for the above approach
#include 
using namespace std;
 
// Function to print prime factors
// of N in decreasing order
void PrimeFactors(int N)
{
    // Stores prime factors of N
    // in decreasing order
    stack st;
 
    int i = 2;
    while (N != 1) {
 
        if (N % i == 0) {
 
            // Insert i into stack
            st.push(i);
 
            while (N % i == 0) {
 
                // Update N
                N = N / i;
            }
        }
 
        // Update i
        i++;
    }
 
    // Print value of stack st
    while (!st.empty()) {
 
        printf("%d ", st.top());
        st.pop();
    }
}
 
// Driver Code
int main()
{
    int N = 8;
 
    // function Call
    PrimeFactors(N);
    return 0;
}

Java

// Java program for the above approach 
import java.util.*;
 
class GFG{
         
// Function to print prime factors
// of N in decreasing order
static void PrimeFactors(int N)
{
     
    // Stores prime factors of N
    // in decreasing order
    Stack st = new Stack<>();
 
    int i = 2;
     
    while (N != 1)
    {
        if (N % i == 0)
        {
             
            // Insert i into stack
            st.push(i);
 
            while (N % i == 0)
            {
                 
                // Update N
                N = N / i;
            }
        }
 
        // Update i
        i++;
    }
 
    // Print value of stack st
    while (!st.isEmpty())
    {
        System.out.println(st.peek());
        st.pop();
    }
}
 
// Driver Code   
public static void main (String[] args)   
{   
    int N = 8;
     
    // Function Call
    PrimeFactors(N);;
}
}
 
// This code is contributed by susmitakundugoaldanga

Python3

# Python3 program for the above approach
 
# Function to print prime factors
# of N in decreasing order
def PrimeFactors(N):
 
    # Stores prime factors of N
    # in decreasing order
    st = []
    i = 2
    while (N != 1):
        if (N % i == 0):
 
            # Insert i into stack
            st.append(i)
            while (N % i == 0):
 
                # Update N
                N = N // i
 
        # Update i
        i += 1
 
    # Print value of stack st
    while (len(st) != 0):
        print(st[-1])
        st.pop()
 
# Driver Code
if __name__ == "__main__":
    N = 8
 
    # function Call
    PrimeFactors(N)
 
    # This code is contributed by chitranayal.

C#

// C# program for the above approach
using System;
using System.Collections.Generic;
 
class GFG{
         
// Function to print prime factors
// of N in decreasing order
static void PrimeFactors(int N)
{
     
    // Stores prime factors of N
    // in decreasing order
    Stack st = new Stack();
 
    int i = 2;
     
    while (N != 1)
    {
        if (N % i == 0)
        {
             
            // Insert i into stack
            st.Push(i);
 
            while (N % i == 0)
            {
                 
                // Update N
                N = N / i;
            }
        }
 
        // Update i
        i++;
    }
 
    // Print value of stack st
    while (st.Count != 0)
    {
        Console.Write(st.Peek());
        st.Pop();
    }
}
 
// Driver Code   
public static void Main ()   
{  
    int N = 8;
     
    // Function Call
    PrimeFactors(N);;
}
}
 
// This code is contributed by code_hunt

输出：

2

时间复杂度： O(sqrt(N))
辅助空间： O(1)