Program to reverse a sentence
Write a program to reverse a sentence.
Examples:
Input: “Practice with GFG”
Output: “GFG htiw ecitcarP”Input: “Programming is fun”
Output: “nuf si gnimmargorP”
Approach: To solve the problem, follow the below idea:
It can be observed that we can reverse a sentence by traversing over the original sentence in reverse order and then pushing the characters from the back to a new string. Finally, return the final string.
Step-by-step algorithm:
- Create a variable to store the reversed sentence.
- Traverse the original sentence from the last character to the first.
- Append each character to the reversed sentence.
Below is the implementation of the algorithm:
C++
#include <iostream> using namespace std; string reverseSentence(string sentence) { string reversedString = "" ; for ( int i = sentence.length() - 1; i >= 0; i--) { reversedString.push_back(sentence[i]); } return reversedString; } int main() { string sentence = "Practice with GFG" ; cout << reverseSentence(sentence) << endl; return 0; } |
C
#include <stdio.h> #include <string.h> char * reverseSentence( const char * sentence) { int length = strlen (sentence); char * reversedString = ( char *) malloc ((length + 1) * sizeof ( char )); for ( int i = length - 1, j = 0; i >= 0; i--, j++) { reversedString[j] = sentence[i]; } reversedString[length] = '\0' ; return reversedString; } int main() { const char * sentence = "Practice with GFG" ; char * reversed = reverseSentence(sentence); printf ( "%s\n" , reversed); free (reversed); // Don't forget to free the allocated memory return 0; } |
Java
public class ReverseSentence { public static String reverseSentence(String sentence) { StringBuilder reversedString = new StringBuilder(); for ( int i = sentence.length() - 1 ; i >= 0 ; i--) { reversedString.append(sentence.charAt(i)); } return reversedString.toString(); } public static void main(String[] args) { String sentence = "Practice with GFG" ; System.out.println(reverseSentence(sentence)); } } |
Python3
def reverse_sentence(sentence): reversed_string = "" for i in range ( len (sentence) - 1 , - 1 , - 1 ): reversed_string + = sentence[i] return reversed_string if __name__ = = "__main__" : sentence = "Practice with GFG" print (reverse_sentence(sentence)) |
C#
using System; class Program { static string ReverseSentence( string sentence) { char [] charArray = sentence.ToCharArray(); Array.Reverse(charArray); return new string (charArray); } static void Main() { string sentence = "Practice with GFG" ; Console.WriteLine(ReverseSentence(sentence)); } } |
Javascript
function reverseSentence(sentence) { return sentence.split( '' ).reverse().join( '' ); } const sentence = "Practice with GFG" ; console.log(reverseSentence(sentence)); |
Output
GFG htiw ecitcarP
Time Complexity: O(N), where N is the length of the sentence.
Auxiliary Space: O(N)
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