Sentence Palindrome (Palindrome after removing spaces, dots, .. etc)

Write a program to check if a sentence is palindrome or not. You can ignore white spaces and other characters to consider sentence as a palindrome.

Examples:

Input : str = "Too hot to hoot."
Output : Sentence is palindrome.

Input : str = "Abc def ghi jklm."
Output : Sentence is not palindrome.

Note that there may be multiple spaces and/or dots between two words.

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

To find if a sentence is palindrome, compare each character from left and right. If they are equal, compare until left and right of string are equal or right becomes less then left. Remember to ignore white spaces and other characters in a string.

C++

// CPP program to find if a sentence is 
// palindrome 
#include <bits/stdc++.h> 
using namespace std; 
   
// To check sentence is palindrome or not 
bool sentencePalindrome(string str) 
{ 
    int l = 0, h = str.length(); 
   
    // Lowercase string 
    for (int i = 0; i < h; i++) 
        str[i] = tolower(str[i]); 
   
    // Compares character until they are equal 
    while (l <= h) { 
   
        // If there is another symbol in left 
        // of sentence 
        if (!(str[l] >= 'a' && str[l] <= 'z')) 
            l++; 
   
        // If there is another symbol in right  
        // of sentence 
        else if (!(str[h] >= 'a' && str[h] <= 'z')) 
            h--; 
   
        // If characters are equal 
        else if (str[l] == str[h]) 
            l++, h--; 
   
        // If characters are not equal then 
        // sentence is not palindrome 
        else
            return false; 
    } 
   
    // Returns true if sentence is palindrome 
    return true; 
} 
   
// Driver program to test sentencePalindrome() 
int main() 
{ 
    string str = "Too hot to hoot."; 
   
    if (sentencePalindrome(str)) 
        cout << "Sentence is palindrome."; 
    else
        cout << "Sentence is not palindrome."; 
   
    return 0; 
} 

Java

// Java program to find if a sentence is 
// palindrome 
public class GFG 
{ 
    // To check sentence is palindrome or not 
    static boolean sentencePalindrome(String str) 
    {     
        int l = 0; 
        int h = str.length()-1; 
          
        // Lowercase string 
        str = str.toLowerCase(); 
          
        // Compares character until they are equal 
        while(l <= h) 
        { 
              
            char getAtl = str.charAt(l); 
            char getAth = str.charAt(h); 
              
            // If there is another symbol in left 
            // of sentence 
            if (!(getAtl >= 'a' && getAtl <= 'z')) 
                l++; 
              
            // If there is another symbol in right  
            // of sentence 
            else if(!(getAth >= 'a' && getAth <= 'z')) 
                h--; 
              
            // If characters are equal 
            else if( getAtl == getAth) 
            { 
                l++; 
                h--; 
            } 
              
            // If characters are not equal then 
            // sentence is not palindrome 
            else 
                return false; 
        } 
          
        // Returns true if sentence is palindrome 
        return true;     
    } 
      
    // Driver program to test sentencePallindrome() 
    public static void main(String[] args)  
    { 
        String str = "Too hot to hoot."; 
        if( sentencePalindrome(str)) 
          System.out.println("Sentence is palindrome"); 
        else
          System.out.println("Sentence is not" + " " + 
                                         "palindrome"); 
    } 
} 
  
//This code is contributed by Sumit Ghosh 

Python

# Python program to find if a sentence is 
# palindrome 
# To check sentence is palindrome or not 
def sentencePalindrome(s): 
    l, h = 0, len(s) - 1
    
    # Lowercase string 
    s = s.lower() 
    
    # Compares character until they are equal 
    while (l <= h): 
    
        # If there is another symbol in left 
        # of sentence 
        if (not(s[l] >= 'a' and s[l] <= 'z')): 
            l += 1
    
        # If there is another symbol in right  
        # of sentence 
        elif (not(s[h] >= 'a' and s[h] <= 'z')): 
            h -= 1
    
        # If characters are equal 
        elif (s[l] == s[h]): 
            l += 1
            h -= 1
          
        # If characters are not equal then 
        # sentence is not palindrome 
        else: 
            return False
    # Returns true if sentence is palindrome 
    return True
    
# Driver program to test sentencePalindrome() 
s = "Too hot to hoot."
if (sentencePalindrome(s)): 
    print "Sentence is palindrome."
else: 
    print "Sentence is not palindrome."
  
# This code is contributed by Sachin Bisht 

C#

// C# program to find if a  
// sentence is palindrome 
using System; 
  
public class GFG 
{ 
      
    // To check sentence is  
    // palindrome or not 
    static bool sentencePalindrome(String str) 
    {  
        int l = 0; 
        int h = str.Length - 1; 
          
        // Lowercase string 
        str = str.ToLower(); 
          
        // Compares character until  
        // they are equal 
        while(l <= h) 
        { 
              
            char getAtl = str[l]; 
            char getAth = str[h]; 
              
            // If there is another symbol  
            // in left of sentence 
            if (!(getAtl >= 'a' &&  
                  getAtl <= 'z')) 
                l++; 
              
            // If there is another symbol   
            // in right of sentence 
            else if(! (getAth >= 'a' && 
                       getAth <= 'z')) 
                h--; 
              
            // If characters are equal 
            else if( getAtl == getAth) 
            { 
                l++; 
                h--; 
            } 
              
            // If characters are not equal then 
            // sentence is not palindrome 
            else
                return false; 
        } 
          
        // Returns true if sentence  
        // is palindrome 
        return true;  
    } 
      
    // Driver Code 
    public static void Main()  
    { 
        String str = "Too hot to hoot."; 
        if( sentencePalindrome(str)) 
        Console.Write("Sentence is palindrome"); 
        else
        Console.Write("Sentence is not" + " " + 
                                     "palindrome"); 
    } 
} 
  
// This code is contributed by Nitin Mittal. 

PHP

<?php  
// PHP program to find if a sentence is 
// palindrome 
    
// To check sentence is palindrome or not 
function sentencePalindrome($str) 
{ 
    $l = 0; 
    $h = strlen($str)-1; 
    
    // Lowercase string 
    for ($i = 0; $i < $h; $i++) 
        $str[$i] = strtolower($str[$i]); 
    
    // Compares character until they are equal 
    while ($l <= $h) { 
    
        // If there is another symbol in left 
        // of sentence 
        if (!($str[$l] >= 'a' && $str[$l] <= 'z')) 
            $l++; 
    
        // If there is another symbol in right  
        // of sentence 
        else if (!($str[$h] >= 'a' && $str[$h] <= 'z')) 
            $h--; 
    
        // If characters are equal 
        else if ($str[$l] == $str[$h]) 
        { 
             $l++; 
            $h--; 
        } 
    
        // If characters are not equal then 
        // sentence is not palindrome 
        else
            return false; 
    } 
    
    // Returns true if sentence is palindrome 
    return true; 
} 
    
// Driver program to test sentencePalindrome() 
  
$str = "Too hot to hoot."; 
  
if (sentencePalindrome($str)) 
    echo "Sentence is palindrome."; 
else
    echo "Sentence is not palindrome."; 
  
return 0; 
?> 

Output:

Sentence is palindrome.

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My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python

C#

PHP

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