Check if given String is Pangram or not

Given a string Str. The task is to check if it is Pangram or not. 

A pangram is a sentence containing every letter in the English Alphabet.

Examples: 

Input: “The quick brown fox jumps over the lazy dog” 
Output: is a Pangram 
Explanation: Contains all the characters from ‘a’ to ‘z’] 

Input: “The quick brown fox jumps over the dog”
Output: is not a Pangram 
Explanation: Doesn’t contain all the characters from ‘a’ to ‘z’, as ‘l’, ‘z’, ‘y’ are missing

Approach 1: Below is the idea to solve the problem

Create a mark[] array of Boolean types and iterate through all the characters of the string and mark it as visited. Lowercase and Uppercase are considered the same. So ‘A’ and ‘a’ are marked in index 0 and similarly ‘Z’ and ‘z’ are marked in index 25.

After iterating through all the characters check whether all the characters are marked or not. If not then return false as this is not a pangram else return true. 

Follow the below steps to Implement the idea:

• Create a bool vector mark[] of size 26.
• Iterate through all characters of the string str and mark str[i] – ‘a’ or str[i] – ‘A’ as 1 for lower and upper characters respectively.
• Iterate through all the indices of mark[] 
  • If all indices are marked visited then return is a Pangram 
  • Else return  is not a Pangram.

Below is the Implementation of above approach

C++

// A C++ Program to check if the given
// string is a pangram or not
#include <bits/stdc++.h>
using namespace std;

// Returns true if the string is pangram else false
bool checkPangram(string& str)
{
    // Create a hash table to mark the characters
    // present in the string
    vector<bool> mark(26, false);
    // For indexing in mark[]
    int index;
    // Traverse all characters
    for (int i = 0; i < str.length(); i++) {
        // If uppercase character, subtract 'A'
        // to find index.
        if ('A' <= str[i] && str[i] <= 'Z')
            index = str[i] - 'A';
        // If lowercase character, subtract 'a'
        // to find index.
        else if ('a' <= str[i] && str[i] <= 'z')
            index = str[i] - 'a';
        // If this character is other than english
        // lowercase and uppercase characters.
        else
            continue;
        mark[index] = true;
    }

    // Return false if any character is unmarked
    for (int i = 0; i <= 25; i++)
        if (mark[i] == false)
            return (false);
    // If all characters were present
    return (true);
}

// Driver Program to test above functions
int main()
{
    string str = "The quick brown fox jumps over the"
                 " lazy dog";
    if (checkPangram(str) == true)
        printf(" %s \nis a pangram", str.c_str());
    else
        printf(" %s \nis not a pangram", str.c_str());
    return (0);
}

// This code is contributed by Aditya kumar (adityakumar129)

C

// A C Program to check if the given
// string is a pangram or not
#include <stdbool.h>
#include <stdio.h>
#include <string.h>

// Returns true if the string is pangram else false
bool checkPangram(char str[])
{
    // Create a hash table to mark the characters
    // present in the string
    bool mark[26];
    for (int i = 0; i < 26; i++)
        mark[i] = false;

    // For indexing in mark[]
    int index;

    // Traverse all characters
    size_t size = strlen(str);
    for (int i = 0; i < size; i++) {

        // If uppercase character, subtract 'A'
        // to find index.
        if ('A' <= str[i] && str[i] <= 'Z')
            index = str[i] - 'A';

        // If lowercase character, subtract 'a'
        // to find index.
        else if ('a' <= str[i] && str[i] <= 'z')
            index = str[i] - 'a';

        // If this character is other than english
        // lowercase and uppercase characters.
        else
            continue;

        mark[index] = true;
    }

    // Return false if any character is unmarked
    for (int i = 0; i <= 25; i++)
        if (mark[i] == false)
            return (false);

    // If all characters were present
    return (true);
}

// Driver Program to test above functions
int main()
{
    char str[]
        = "The quick brown fox jumps over the lazy dog";
    if (checkPangram(str) == true)
        printf(" %s \nis a pangram", str);
    else
        printf(" %s \nis not a pangram", str);
    return (0);
}

// This code is contributed by Aditya kumar (adityakumar129)

Java

// Java Program to illustrate Pangram

import java.io.*;

class GFG {

    // Returns true if the string
    // is pangram else false
    public static boolean checkPangram(String str)
    {
        // Create a hash table to mark the
        // characters present in the string
        // By default all the elements of
        // mark would be false.
        boolean[] mark = new boolean[26];

        // For indexing in mark[]
        int index = 0;

        // Traverse all characters
        for (int i = 0; i < str.length(); i++) {
            // If uppercase character, subtract 'A'
            // to find index.
            if ('A' <= str.charAt(i)
                && str.charAt(i) <= 'Z')
                index = str.charAt(i) - 'A';

            // If lowercase character, subtract 'a'
            // to find index.
            else if ('a' <= str.charAt(i)
                     && str.charAt(i) <= 'z')

                index = str.charAt(i) - 'a';

            // If this character is other than english
            // lowercase and uppercase characters.
            else
                continue;
            mark[index] = true;
        }

        // Return false if any character is unmarked
        for (int i = 0; i <= 25; i++)
            if (mark[i] == false)
                return (false);

        // If all characters were present
        return (true);
    }

    // Driver Code
    public static void main(String[] args)
    {
        String str
            = "The quick brown fox jumps over the lazy dog";

        if (checkPangram(str) == true)
            System.out.print(str + " \nis a pangram.");
        else
            System.out.print(str + " \nis not a pangram.");
    }
}

Python3

# A Python Program to check if the given
# string is a pangram or not


def checkPangram(s):
    List = []
    # create list of 26 characters and set false each entry
    for i in range(26):
        List.append(False)

    # converting the sentence to lowercase and iterating
    # over the sentence
    for c in s.lower():
        if not c == " ":

            # make the corresponding entry True
            List[ord(c) - ord('a')] = True

    # check if any character is missing then return False
    for ch in List:
        if ch == False:
            return False
    return True


# Driver Program to test above functions
sentence = "The quick brown fox jumps over the little lazy dog"

if (checkPangram(sentence)):
    print('"'+sentence+'"')
    print("\nis a pangram")
else:
    print('"'+sentence+'"')
    print("\nis not a pangram")

# This code is contributed by Danish Mushtaq

C#

// C# Program to illustrate Pangram
using System;
class GFG {

    // Returns true if the string
    // is pangram else false
    public static bool checkPangram(string str)
    {

        // Create a hash table to mark the
        // characters present in the string
        // By default all the elements of
        // mark would be false.
        bool[] mark = new bool[26];

        // For indexing in mark[]
        int index = 0;

        // Traverse all characters
        for (int i = 0; i < str.Length; i++) {
            // If uppercase character, subtract 'A'
            // to find index.
            if ('A' <= str[i] && str[i] <= 'Z')
                index = str[i] - 'A';

            // If lowercase character,
            // subtract 'a' to find
            // index.
            else if ('a' <= str[i] && str[i] <= 'z')
                index = str[i] - 'a';

            // If this character is other than english
            // lowercase and uppercase characters.
            else
                continue;

            mark[index] = true;
        }

        // Return false if any
        // character is unmarked
        for (int i = 0; i <= 25; i++)
            if (mark[i] == false)
                return (false);

        // If all characters
        // were present
        return (true);
    }

    // Driver Code
    public static void Main()
    {
        string str
            = "The quick brown fox jumps over the lazy dog";

        if (checkPangram(str) == true)
            Console.WriteLine(str + " \nis a pangram.");
        else
            Console.WriteLine(str + " \nis not a pangram.");
    }
}

// This code is contributed by nitin mittal.

Javascript

<script>

// A JavaScript Program to check if the given
// string is a pangram or not


// Returns true if the string is pangram else false
function checkPangram(str)
{
    // Create a hash table to mark the characters
    // present in the string
    mark = new Array(26).fill(false);

    // For indexing in mark[]
    let index;

    // Traverse all characters
    for (let i = 0; i < str.length; i++) {

        // If uppercase character, subtract 'A'
        // to find index.
        if ('A' <= str[i] && str[i] <= 'Z')
            index = str.charCodeAt(i) - 'A'.charCodeAt(0);

        // If lowercase character, subtract 'a'
        // to find index.
        else if ('a' <= str[i] && str[i] <= 'z')
             index = str.charCodeAt(i) - 'a'.charCodeAt(0);

        // If this character is other than english
        // lowercase and uppercase characters.
        else continue;

        mark[index] = true;
    }

    // Return false if any character is unmarked
    for (let i = 0; i <= 25; i++)
        if (mark[i] == false)
            return false;

    // If all characters were present
    return true;
}

// Driver Program to test above functions

let str = "The quick brown fox jumps over the lazy dog";

document.write(str,"</br>")

if (checkPangram(str) == true)
    document.write("\nis a pangram");
else
    document.write("\nis not a pangram");

// This code is contributed by shinjanpatra.
</script>

Output

 The quick brown fox jumps over the lazy dog 
is a pangram

Time Complexity : O(n), where n is the length of our string 
Auxiliary Space: O(1), as 26 size Boolean vector is constant. 

Approach 2 (Using Set) : The idea to use a set is quite obvious because to check a pangram, there must be 26 alphabets no matter whether it is a lowercase or uppercase character. To check whether a alphabet is already present or not, the alphabets have been inserted in lowercase and the set size must be 26.

Follow the below steps to Implement the idea :

• Initialize a character set.
• Traverse over the string and check for each character.
• If the character is an lowercase alphabet then insert in the set.
• In case it is a uppercase alphabet convert it in lowercase using the tolower() function and then insert it.
• At the end simply check whether the set size is 26 or not. If it’s true that means all alphabets in either lowercase or uppercase was present in the string. 

Below is the code for the following approach : 

C++

// A C++ Program to check if the given
// string is a pangram or not
#include <bits/stdc++.h>
using namespace std;

// Returns true if the string is pangram else false
bool checkPangram(string& str)
{
    // Initialize a set of characters
    set<char> set;

    for (auto ch : str) {
        // If the character is already
        // a lowercase character
        if (ch >= 'a' and ch <= 'z')
            set.insert(ch);

        // In case of a uppercase character
        if (ch >= 'A' and ch <= 'Z') {
            // convert to lowercase
            ch = tolower(ch);
            set.insert(ch);
        }
    }

    // check if the size is 26 or not
    return set.size() == 26;
}

// Driver Program to test above functions
int main()
{
    string str = "The quick brown fox jumps over the"
                 " lazy dog";
    if (checkPangram(str) == true)
        cout << "It is a Pangram" << endl;
    else
        cout << "It is Not a Pangram" << endl;

    return 0;
}

// This code is contributed by Rajdeep Mallick
// (rajdeepmallick999)

Java

// A Java Program to check if the given
// string is a pangram or not
import java.util.*;

public class Gfg {

    // Returns true if the string is pangram else false
    static boolean checkPangram(String str) {
        // Initialize a set of characters
        Set<Character> set = new HashSet<>();

        for (char ch : str.toCharArray()) {
            // If the character is already
            // a lowercase character
            if (ch >= 'a' && ch <= 'z')
                set.add(ch);

            // In case of a uppercase character
            if (ch >= 'A' && ch <= 'Z') {
                // convert to lowercase
                ch = Character.toLowerCase(ch);
                set.add(ch);
            }
        }

        // check if the size is 26 or not
        return set.size() == 26;
    }

    // Driver Program to test above functions
    public static void main(String[] args) {
        String str = "The quick brown fox jumps over the lazy dog";
        if (checkPangram(str))
            System.out.println("It is a Pangram");
        else
            System.out.println("It is Not a Pangram");
    }
}

Python3

#A Python3 Program to check if the given
#string is a pangram or not
#Returns true if the string is pangram else false
def checkPangram(string):
    # Initialize a set of characters
    char_set = set()

    for ch in string:
        # If the character is already
        # a lowercase character
        if ch >= 'a' and ch <= 'z':
            char_set.add(ch)

        # In case of a uppercase character
        if ch >= 'A' and ch <= 'Z':
            # convert to lowercase
            ch = ch.lower()
            char_set.add(ch)

    # check if the size is 26 or not
    return len(char_set) == 26

#Driver Program to test above functions
string = "The quick brown fox jumps over the lazy dog"
if checkPangram(string) == True:
    print("It is a Pangram")
else:
    print("It is Not a Pangram")

C#

using System;
using System.Collections.Generic;

class Program
{
    static bool CheckPangram(string str)
    {
        // Initialize a set of characters
        HashSet<char> set = new HashSet<char>();

        foreach (char ch in str)
        {
            // If the character is already a lowercase character
            if (ch >= 'a' && ch <= 'z')
                set.Add(ch);

            // In case of an uppercase character
            if (ch >= 'A' && ch <= 'Z')
            {
                // convert to lowercase
                char lowerCh = Char.ToLower(ch);
                set.Add(lowerCh);
            }
        }

        // check if the size is 26 or not
        return set.Count == 26;
    }

    static void Main()
    {
        string str = "The quick brown fox jumps over the lazy dog";
        if (CheckPangram(str))
            Console.WriteLine("It is a Pangram");
        else
            Console.WriteLine("It is Not a Pangram");
    }
}

Javascript

// THIS CODE IS CONTRIBUTED BY YASH AGARWAL(YASHAGARWAL2852002)
// Returns true if the string is pangram else false
function checkPangram(str) {
    // Initialize a set of characters
    const set = new Set();

    for (let ch of str) {
        // If the character is already
        // a lowercase character
        if (ch >= 'a' && ch <= 'z') {
            set.add(ch);
        }

        // In case of an uppercase character
        if (ch >= 'A' && ch <= 'Z') {
            // convert to lowercase
            ch = ch.toLowerCase();
            set.add(ch);
        }
    }

    // check if the size is 26 or not
    return set.size === 26;
}

// Driver Program to test above functions
const str = "The quick brown fox jumps over the lazy dog";
if (checkPangram(str)) {
    console.log("It is a Pangram");
} else {
    console.log("It is Not a Pangram");
}

Output

It is a Pangram

Time Complexity : O(NlogN), for traversing whole string and inserting all the characters at worst case takes logN time.
Space Complexity : O(1), using constant space for 26 characters at most.

This article is contributed by Rachit Belwariar. If you like GeeksforGeeks and would like to contribute, you can also write an article and mail your article to review-team@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.