Update Pangram.java

Author: preritasaini1

src/main/java/com/thealgorithms/strings/Pangram.java

@@ -1,103 +1,36 @@
-package com.thealgorithms.strings;
-
-import java.util.HashSet;
-
-/**
- * Checks if a given string is a Pangram (a sentence containing every letter of the alphabet at least once).
- * Wikipedia: https://en.wikipedia.org/wiki/Pangram
- */
-public final class Pangram {
-
-    private Pangram() {
-    }
-
-    /**
-     * Main method to test all pangram-checking methods.
-     */
-    public static void main(String[] args) {
-        assert isPangram("The quick brown fox jumps over the lazy dog");
-        assert !isPangram("The quick brown fox jumps over the azy dog"); // L is missing
-        assert !isPangram("+-1234 This string is not alphabetical");
-        assert !isPangram("\u0000/\\");
-        assert isPangramUsingBitwise("The quick brown fox jumps over the lazy dog");
-        assert !isPangramUsingBitwise("Hello, World!");
-    }
-
-    /**
-     * Checks if a String is a Pangram using a HashSet to track unique characters.
-     *
-     * @param s The String to check
-     * @return {@code true} if s is a Pangram, otherwise {@code false}
-     */
-    public static boolean isPangramUsingSet(String s) {
-        HashSet<Character> uniqueChars = new HashSet<>();
-        s = s.toLowerCase();
-        for (char c : s.toCharArray()) {
-            if (c >= 'a' && c <= 'z') {
-                uniqueChars.add(c);
-            }
-        }
-        return uniqueChars.size() == 26;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+public class PangramTest {
+
+    @Test
+    public void testIsPangram() {
+        assertTrue(Pangram.isPangram("The quick brown fox jumps over the lazy dog"));
+        assertFalse(Pangram.isPangram("The quick brown fox jumps over the azy dog")); // L is missing
+        assertFalse(Pangram.isPangram("+-1234 This string is not alphabetical"));
+        assertFalse(Pangram.isPangram("\u0000/\\"));
     }
 
-    /**
-     * Checks if a String is a Pangram by tracking occurrences of each letter in an array.
-     *
-     * @param s The String to check
-     * @return {@code true} if s is a Pangram, otherwise {@code false}
-     */
-    public static boolean isPangram(String s) {
-        boolean[] lettersExisting = new boolean[26];
-        s = s.toLowerCase();
-        for (char c : s.toCharArray()) {
-            if (c >= 'a' && c <= 'z') {
-                lettersExisting[c - 'a'] = true;
-            }
-        }
-        for (boolean letterFlag : lettersExisting) {
-            if (!letterFlag) {
-                return false;
-            }
-        }
-        return true;
+    @Test
+    public void testIsPangramUsingSet() {
+        assertTrue(Pangram.isPangramUsingSet("The quick brown fox jumps over the lazy dog"));
+        assertFalse(Pangram.isPangramUsingSet("The quick brown fox jumps over the azy dog")); // L is missing
+        assertFalse(Pangram.isPangramUsingSet("+-1234 This string is not alphabetical"));
+        assertFalse(Pangram.isPangramUsingSet("\u0000/\\"));
     }
 
-    /**
-     * Checks if a String is a Pangram by checking each letter in the alphabet individually.
-     *
-     * @param s The String to check
-     * @return {@code true} if s is a Pangram, otherwise {@code false}
-     */
-    public static boolean isPangram2(String s) {
-        if (s.length() < 26) {
-            return false;
-        }
-        s = s.toLowerCase();
-        for (char i = 'a'; i <= 'z'; i++) {
-            if (s.indexOf(i) == -1) {
-                return false; // if any alphabet is missing, return false
-            }
-        }
-        return true;
+    @Test
+    public void testIsPangram2() {
+        assertTrue(Pangram.isPangram2("The quick brown fox jumps over the lazy dog"));
+        assertFalse(Pangram.isPangram2("The quick brown fox jumps over the azy dog")); // L is missing
+        assertFalse(Pangram.isPangram2("+-1234 This string is not alphabetical"));
+        assertFalse(Pangram.isPangram2("\u0000/\\"));
     }
 
-    /**
-     * Optimized Pangram check using Bitwise operations.
-     * Each bit in a 32-bit integer represents a unique letter from 'a' to 'z'.
-     *
-     * @param s The String to check
-     * @return {@code true} if s is a Pangram, otherwise {@code false}
-     */
-    public static boolean isPangramUsingBitwise(String s) {
-        int checker = 0;
-        s = s.toLowerCase();
-        for (char c : s.toCharArray()) {
-            if (c >= 'a' && c <= 'z') {
-                int bitIndex = c - 'a';
-                checker |= (1 << bitIndex);
-            }
-        }
-        // If all 26 bits are set, checker will equal 0b11111111111111111111111111 (26 ones)
-        return checker == (1 << 26) - 1;
+    @Test
+    public void testIsPangramUsingBitwise() {
+        assertTrue(Pangram.isPangramUsingBitwise("The quick brown fox jumps over the lazy dog"));
+        assertFalse(Pangram.isPangramUsingBitwise("Hello, World!"));
     }
 }