# Reverse words in a given string | Set 2

• Difficulty Level : Medium
• Last Updated : 26 Sep, 2021

Given string str, the task is to reverse the string by considering each word of the string, str as a single unit.

Examples:

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Input: str = “geeks quiz practice code”
Output: code practice quiz geeks
Explanation:
The words in the given string are [“geeks”, “quiz”, “practice”,  “code”].
Therefore, after reversing the order of the words, the required output is“code practice quiz geeks”.

Input: str = “getting good at coding needs a lot of practice”
Output: practice of lot a needs coding at good getting

In-place Reversal Approach: Refer to the article Reverse words in a given string for the in-place reversal of words followed by a reversal of the entire string.

Time Complexity: O(N)
Auxiliary Space: O(1)

Stack-based Approach: In this article, the approach to solving the problem using Stack is going to be discussed. The idea here is to push all the words of str into the Stack and then print all the elements of the Stack. Follow the steps below to solve the problem:

1. Create a Stack to store each word of the string str.
2. Iterate over string str, and separate each word of str by a space delimiter.
3. Push all the words of str into the stack.
4. Print all the elements of the stack one by one.

Below is the implementation of the above approach:

## C++

 `// C++ Program to implement``// the above approach` `#include ``using` `namespace` `std;` `// Function to reverse the words``// of a given string``void` `printRev(string str)``{``    ``// Stack to store each``    ``// word of the string``    ``stack st;` `    ``// Store the whole string``    ``// in string stream``    ``stringstream ss(str);` `    ``string temp;``    ``while` `(getline(ss, temp, ``' '``)) {` `        ``// Push each word of the``        ``// string into the stack``        ``st.push(temp);``    ``}` `    ``// Print the string in reverse``    ``// order of the words``    ``while` `(!st.empty()) {``        ``cout << st.top() << ``" "``;``        ``st.pop();``    ``}``}` `// Driver Code``int` `main()``{``    ``string str;``    ``str = ``"geeks quiz practice code"``;` `    ``printRev(str);``    ``return` `0;``}`

## Java

 `// Java Program to implement``// the above approach``import` `java.util.*;``class` `GFG{` `    ``// Function to reverse the words``    ``// of a given String``    ``static` `void` `printRev(String str)``    ``{``        ``// Stack to store each``        ``// word of the String``        ``Stack st = ``new` `Stack();` `        ``// Store the whole String``        ``// in String stream``        ``String[] ss = str.split(``" "``);` `        ``for` `(String temp : ss)``        ``{` `            ``// Push each word of the``            ``// String into the stack``            ``st.add(temp);``        ``}` `        ``// Print the String in reverse``        ``// order of the words``        ``while` `(!st.isEmpty())``        ``{``            ``System.out.print(st.peek() + ``" "``);``            ``st.pop();``        ``}``    ``}` `    ``// Driver Code``    ``public` `static` `void` `main(String[] args)``    ``{``        ``String str;``        ``str = ``"geeks quiz practice code"``;``        ``printRev(str);``    ``}``}` `// This code is contributed by Rajput-Ji`

## Python3

 `# Python3 program to implement``# the above approach` `# Function to reverse the words``# of a given string``def` `printRev(strr):``    ` `    ``# Stack to store each``    ``# word of the string``    ``strr ``=` `strr.split(``" "``)``    ``st ``=` `[]` `    ``# Store the whole string``    ``# in stream``    ``for` `i ``in` `strr:` `        ``# Push each word of the``        ``# into the stack``        ``st.append(i)` `    ``# Print the in reverse``    ``# order of the words``    ``while` `len``(st) > ``0``:``        ``print``(st[``-``1``], end ``=` `" "``)``        ``del` `st[``-``1``]` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:``    ` `    ``strr ``=` `"geeks quiz practice code"``    ` `    ``printRev(strr)` `# This code is contributed by mohit kumar 29`

## C#

 `// C# program to implement``// the above approach``using` `System;``using` `System.Collections;` `class` `GFG{` `// Function to reverse the words``// of a given String``static` `void` `printRev(``string` `str)``{``    ` `    ``// Stack to store each``    ``// word of the String``    ``Stack st = ``new` `Stack();` `    ``String[] separator = {``" "``};``    ` `    ``// Store the whole String``    ``// in String stream``    ``string``[] ss = str.Split(separator,``                            ``int``.MaxValue,``             ``StringSplitOptions.RemoveEmptyEntries);` `    ``foreach``(``string` `temp ``in` `ss)``    ``{` `        ``// Push each word of the``        ``// String into the stack``        ``st.Push(temp);``    ``}` `    ``// Print the String in reverse``    ``// order of the words``    ``while` `(st.Count > 0)``    ``{``        ``Console.Write(st.Peek() + ``" "``);``        ``st.Pop();``    ``}``}` `// Driver Code``public` `static` `void` `Main(``string``[] args)``{``    ``string` `str;``    ``str = ``"geeks quiz practice code"``;``    ` `    ``printRev(str);``}``}` `// This code is contributed by rutvik_56`

## Javascript

 ``
Output
`code practice quiz geeks `

Time Complexity: O(N), where N denotes the length of the string.
Auxiliary Space: O(N)

#### Method #2: Using built-in python functions

• As all the words in a sentence are separated by spaces.
• We have to split the sentence by spaces using split().
• We split all the words by spaces and store them in a list.
• Reverse this list and print it.

## C++

 `// C++ program to implement``// the above approach``#include ``using` `namespace` `std;` `// Function to reverse the words``// of a given string``void` `printRev(string lis[])``{``  ` `    ``// reverse the list``    ``reverse(lis, lis + 4);``     ` `    ``for``(``int` `i = 0; i < 4; i++)``    ``{``        ``cout << lis[i] << ``" "``;``    ``}``}``    ` `int` `main()``{``    ``string strr[] = {``"geeks"``, ``"quiz"``, ``"practice"``, ``"code"``};``  ` `    ``printRev(strr);` `    ``return` `0;``}` `// This code is contributed by divyeshrabadiya07.`

## Java

 `// Java program to implement``// the above approach``import` `java.util.*;` `class` `GFG{``    ` `// Function to reverse the words``// of a given string``static` `void` `printRev(String string)``{``    ` `    ``// Split by space and converting``    ``// string to list``    ``String[] lis = string.split(``" "``, ``0``);``     ` `    ``// Reverse the list``    ``Collections.reverse(Arrays.asList(lis));``     ` `    ``// Printing the list``    ``for``(String li : lis)``    ``{``        ``System.out.print(li + ``" "``);``    ``}``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``String strr = ``"geeks quiz practice code"``;` `    ``printRev(strr);``}``}` `// This code is contributed by decode2207`

## Python3

 `# Python3 program to implement``# the above approach` `# Function to reverse the words``# of a given string`  `def` `printRev(string):``    ``# split by space and converting``    ``# string to list``    ``lis ``=` `list``(string.split())``    ``# reverse the list``    ``lis.reverse()``    ``# printing the list``    ``print``(``*``lis)`  `# Driver Code``if` `__name__ ``=``=` `'__main__'``:` `    ``strr ``=` `"geeks quiz practice code"` `    ``printRev(strr)` `# This code is contributed by vikkycirus`

## C#

 `// C# program to implement``// the above approach``using` `System;``class` `GFG {``    ` `    ``// Function to reverse the words``    ``// of a given string``    ``static` `void` `printRev(``string` `String)``    ``{``        ``// split by space and converting``        ``// string to list``        ``string``[] lis = String.Split(``' '``);``        ` `        ``// reverse the list``        ``Array.Reverse(lis);``        ` `        ``// printing the list``        ``foreach``(``string` `li ``in` `lis)``        ``{``            ``Console.Write(li + ``" "``);``        ``}``    ``}` `  ``static` `void` `Main() {``    ``string` `strr = ``"geeks quiz practice code"``;`` ` `    ``printRev(strr);``  ``}``}` `// This code is contributed by rameshtravel07.`

## Javascript

 ``
Output
`code practice quiz geeks`

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