Merge branch 'master' into master

siriak · web-flow · commit 02409a527c88 · 2022-03-30T20:33:07.000+03:00
diff --git a/src/main/java/com/thealgorithms/datastructures/lists/SinglyLinkedList.java b/src/main/java/com/thealgorithms/datastructures/lists/SinglyLinkedList.java
@@ -54,6 +54,54 @@ public boolean detectLoop() {
         return false;
     }
 
+    /**
+     * Swaps nodes of two given values a and b.
+  *
+     */
+    public void swapNodes(int valueFirst, int valueSecond) {
+        if(valueFirst ==  valueSecond){
+            return;
+        }
+        Node previousA = null ,currentA = head;
+        while(currentA != null && currentA.value != valueFirst){
+            previousA = currentA;
+            currentA = currentA.next;
+        }
+
+        Node previousB = null ,currentB = head;
+        while(currentB != null && currentB.value != valueSecond){
+            previousB = currentB;
+            currentB = currentB.next;
+        }
+        /** If either of 'a' or 'b' is not present, then return */
+        if(currentA == null || currentB == null){
+            return;
+        }
+
+        // If 'a' is not head node of list
+        if(previousA != null){
+            previousA.next = currentB;
+        }
+        else{ 
+            // make 'b' as the new head
+            head = currentB;
+        }
+
+        // If 'b' is not head node of list
+        if(previousB != null){
+            previousB.next = currentA;
+        }
+        else{
+            // Make 'a' as new head
+            head = currentA;
+        }
+        // Swap next pointer
+        
+        Node temp = currentA.next;
+        currentA.next = currentB.next;
+        currentB.next = temp;
+    }
+
     /**
      * Reverse a singly linked list from a given node till the end
      *
diff --git a/src/main/java/com/thealgorithms/datastructures/stacks/DuplicateBrackets.java b/src/main/java/com/thealgorithms/datastructures/stacks/DuplicateBrackets.java
@@ -38,6 +38,7 @@ public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         String str = sc.nextLine();
         System.out.println(check(str));
+        sc.close();
     }
 
 }
diff --git a/src/test/java/com/thealgorithms/strings/AlphabeticalTest.java b/src/test/java/com/thealgorithms/strings/AlphabeticalTest.java
@@ -0,0 +1,30 @@
+package com.thealgorithms.strings;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+public class AlphabeticalTest {
+    @Test
+    public void isAlphabetical() {
+        // expected to be true
+        String input1 = "abcdefghijklmno";
+        String input2 = "abcdxxxyzzzz";
+        String input3 = "fpw";
+
+        // expected to be false
+        String input4 = "123a";
+        String input5 = "abcABC";
+        String input6 = "abcdefghikjlmno";
+
+        assertTrue(Alphabetical.isAlphabetical(input1));
+        assertTrue(Alphabetical.isAlphabetical(input2));
+        assertTrue(Alphabetical.isAlphabetical(input3));
+
+        assertFalse(Alphabetical.isAlphabetical(input4));
+        assertFalse(Alphabetical.isAlphabetical(input5));
+        assertFalse(Alphabetical.isAlphabetical(input6));
+    }
+
+}
diff --git a/src/test/java/com/thealgorithms/strings/PangramTest.java b/src/test/java/com/thealgorithms/strings/PangramTest.java
@@ -0,0 +1,24 @@
+package com.thealgorithms.strings;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+public class PangramTest {
+    @Test
+    public void isPangram() {
+        String fullAlphabet = "abcdefghijklmnopqrstuvwxyz";
+        String notFullAlphabet = "abcdefghiklmnopqrstuvwxyz";
+        String fullMixedCaseAlphabet = "a BCDE fghIjkLMnop qrSTuv WXYz";
+        String sentence1 = "The quick brown fox jumps over the lazy dog";
+        String sentence2 = "The quick brown fox jumps over the lazy gentleman";  // missing letter d
+
+        assertTrue(Pangram.isPangram(fullAlphabet));
+        assertFalse(Pangram.isPangram(notFullAlphabet));
+        assertTrue(Pangram.isPangram(fullMixedCaseAlphabet));
+        assertTrue(Pangram.isPangram(sentence1));
+        assertFalse(Pangram.isPangram(sentence2));
+
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -38,6 +38,7 @@ public static void main(String[] args) throws Exception {`
`38`	`38`	`Scanner sc = new Scanner(System.in);`
`39`	`39`	`String str = sc.nextLine();`
`40`	`40`	`System.out.println(check(str));`
	`41`	`+ sc.close();`
`41`	`42`	`}`
`42`	`43`
`43`	`44`	`}`