Pangram Checking

1.7

Given a string check if it is Pangram or not. A pangram is a sentence containing every letter in the English Alphabet.

Examples : The quick brown fox jumps over the lazy dog ” is a Pangram [Contains all the characters from ‘a’ to ‘z’]
“The quick brown fox jumps over the dog” is not a Pangram [Doesn’t contains all the characters from ‘a’ to ‘z’, as ‘l’, ‘z’, ‘y’ are missing]

We create a mark[] array of Boolean type. We iterate through all the characters of our string and whenever we see a character we mark it. 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 we check whether all the characters are marked or not. If not then return false as this is not a pangram else return true.

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';

        // Mark current character
        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" is a pangram", str.c_str());
    else
        printf (""%s" is not a pangram", str.c_str());

    return(0);
}

Python

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

def checkPangram(s):
    List = []
    # create list of 26 charecters 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 charecter 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 "is a pangram"
else:
    print '"'+sentence+'"'
    print "is not a pangram"

# This code is contributed by Danish Mushtaq  


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).

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 contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above

GATE CS Corner    Company Wise Coding Practice

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.

Recommended Posts:



1.7 Average Difficulty : 1.7/5.0
Based on 53 vote(s)










Writing code in comment? Please use ide.geeksforgeeks.org, generate link and share the link here.