从下到上打印堆栈元素

给定堆栈s，任务是从下到上打印堆栈中的元素，以使元素仍然存在于堆栈中，而其顺序在堆栈中没有更改。

例子：

Input : 
       
       
|   4    |
|   3    |
|   2    |
|   1    |
|________|

Output :1 2 3 4

方法1(递归)：想法是弹出堆栈的元素并调用递归函数PrintStack。一旦堆栈变空，就开始打印最后弹出的元素，最后弹出的元素是最底部的元素。因此，元素将从下至上打印。现在推回已打印的元素，这将保留堆栈中元素的顺序。

下面是上述方法的实现：

C++

// C++ program to print the elements of a
// stack from bottom to top
#include 
using namespace std;
 
// Recursive function to print stack elements
// from bottom to top without changing
// their order
void PrintStack(stack s)
{
    // If stack is empty then return
    if (s.empty())
        return;
     
 
    int x = s.top();
 
    // Pop the top element of the stack
    s.pop();
 
    // Recursively call the function PrintStack
    PrintStack(s);
 
    // Print the stack element starting
    // from the bottom
    cout << x << " ";
 
    // Push the same element onto the stack
    // to preserve the order
    s.push(x);
}
 
// Driver code
int main()
{
    // Stack s
    stack s;
 
    s.push(1);
    s.push(2);
    s.push(3);
    s.push(4);
 
    PrintStack(s);
 
    return 0;
}

Java

// Java program to print the elements of a
// stack from bottom to top
import java.util.*;
 
class GfG
{
 
// Recursive function to print stack elements
// from bottom to top without changing
// their order
static void PrintStack(Stack s)
{
    // If stack is empty then return
    if (s.isEmpty())
        return;
     
    int x = s.peek();
 
    // Pop the top element of the stack
    s.pop();
 
    // Recursively call the function PrintStack
    PrintStack(s);
 
    // Print the stack element starting
    // from the bottom
    System.out.print(x + " ");
 
    // Push the same element onto the stack
    // to preserve the order
    s.push(x);
}
 
// Driver code
public static void main(String[] args)
{
    // Stack s
    Stack s = new Stack ();
 
    s.push(1);
    s.push(2);
    s.push(3);
    s.push(4);
 
    PrintStack(s);
}
}
 
// This code is contributed by Prerna Saini.

Python3

# Python3 program to print the elements of a
# stack from bottom to top
 
# Stack class with all functionality of a stack
import sys
class Stack:
    def __init__(self):
        self.s = []
 
    def push(self, data):
        self.s.append(data)
     
    def pop(self):
        return self.s.pop()
 
    def peek(self):
        return self.s[-1]
    def count(self):
        return len(self.s)
 
# Recursive function to print stack elements
# from bottom to top without changing
# their order
def printStack(s):
     
    # if stack is empty then simply return
    if s.count() == 0:
        return
    x = s.peek()
 
    # pop top most element of the stack
    s.pop()
     
    # recursively call the function printStack
    printStack(s)
     
    # Print the stack element starting
    # from the bottom
    print("{} ".format(x), end = "")
     
    # Push the same element onto the stack
    # to preserve the order
    s.push(x)
 
# Driver code
if __name__=='__main__':
    s=Stack()
    s.push(1)
    s.push(2)
    s.push(3)
    s.push(4)
 
    printStack(s)
 
# This code is contributed by Vikas Kumar

C#

// C# program to print the elements of a
// stack from bottom to top
using System;
using System.Collections.Generic;
 
class GfG
{
 
// Recursive function to print stack elements
// from bottom to top without changing
// their order
static void PrintStack(Stack s)
{
    // If stack is empty then return
    if (s.Count == 0)
        return;
     
    int x = s.Peek();
 
    // Pop the top element of the stack
    s.Pop();
 
    // Recursively call the function PrintStack
    PrintStack(s);
 
    // Print the stack element starting
    // from the bottom
    Console.Write(x + " ");
 
    // Push the same element onto the stack
    // to preserve the order
    s.Push(x);
}
 
// Driver code
public static void Main()
{
    // Stack s
    Stack s = new Stack ();
 
    s.Push(1);
    s.Push(2);
    s.Push(3);
    s.Push(4);
 
    PrintStack(s);
}
}
 
/* This code contributed by PrinciRaj1992 */

输出：

1 2 3 4

方法2(使用另一个堆栈)：想法是将每个元素推入另一个临时堆栈，然后打印该临时堆栈的元素。

C++

// C++ program to print the elements of a
// stack from bottom to top
#include 
using namespace std;
 
// Recursive function to print stack elements
// from bottom to top without changing
// their order
void PrintStack(stack s)
{
    stack temp;
    while (s.empty() == false)
    {
        temp.push(s.top());
        s.pop();
    }  
 
    while (temp.empty() == false)
    {
        int t = temp.top();
        cout << t << " ";
        temp.pop();
 
        // To restore contents of
        // the original stack.
        s.push(t); 
    }
}
 
// Driver code
int main()
{
    // Stack s
    stack s;
 
    s.push(1);
    s.push(2);
    s.push(3);
    s.push(4);
 
    PrintStack(s);
 
    return 0;
}

Java

// Java program to print the
// elements of a stack from
// bottom to top
import java.util.*;
class Main{
   
// Recursive function to print
// stack elements from bottom
// to top without changing
// their order
public static void PrintStack(Stack s)
{
  Stack temp = new Stack();
   
  while (s.empty() == false)
  {
    temp.push(s.peek());
    s.pop();
  }  
 
  while (temp.empty() == false)
  {
    int t = temp.peek();
    System.out.print(t + " ");
    temp.pop();
 
    // To restore contents of
    // the original stack.
    s.push(t); 
  }
}
 
// Driver code
public static void main(String[] args)
{
  // Stack s
  Stack s = new Stack();
 
  s.push(1);
  s.push(2);
  s.push(3);
  s.push(4);
  PrintStack(s);
}
}
 
// This code is contributed by divyeshrabadiya07

Python3

# Python3 program to print the elements of a
# stack from bottom to top
 
# Stack class with all functionality of a stack
import sys
class Stack:
    def __init__(self):
        self.s = []
 
    def push(self, data):
        self.s.append(data)
     
    def pop(self):
        return self.s.pop()
 
    def peek(self):
        return self.s[-1]
    def count(self):
        return len(self.s)
 
# Recursive function to print stack elements
# from bottom to top without changing
# their order
def printStack(s):
    temp = Stack()
    while(s.count() > 0):
        temp.push(s.peek())
        s.pop()
     
    while(temp.count() > 0):
        t = temp.peek()
        print("{} " . format(temp.peek()), end = "")
        temp.pop()
 
        # Restore the contents of original stack
        s.push(t)
 
# Driver code
if __name__=='__main__':
    s = Stack()
    s.push(1)
    s.push(2)
    s.push(3)
    s.push(4)
 
    printStack(s)
 
# This code is contributed by Vikash Kumar 37

C＃

// C# program to print the elements of
// a stack from bottom to top
using System;
using System.Collections;
 
class GFG{
 
// Recursive function to print stack
// elements from bottom to top without
// changing their order
static void PrintStack(Stack s)
{
    Stack temp = new Stack();
    while (s.Count != 0)
    {
        temp.Push(s.Peek());
        s.Pop();
    }  
  
    while (temp.Count != 0)
    {
        int t = (int)temp.Peek();
        Console.Write(t + " ");
        temp.Pop();
  
        // To restore contents of
        // the original stack.
        s.Push(t); 
    }
}
 
// Driver Code
public static void Main(string[] args)
{
     
    // Stack s
    Stack s = new Stack();
    s.Push(1);
    s.Push(2);
    s.Push(3);
    s.Push(4);
 
    PrintStack(s);
}
}
 
// This code is contributed by rutvik_56

输出：

1 2 3 4