javaistic · arghyaxcodes · Oct 23, 2025 · Oct 18, 2025 · Oct 18, 2025 · Oct 20, 2025
diff --git a/content/programs/java-program-to-check-armstrong-number.mdx b/content/programs/java-program-to-check-armstrong-number.mdx
@@ -0,0 +1,228 @@
+---
+title: Java Program to Check Armstrong Number
+shortTitle: Check Armstrong Number
+description: Learn how to check if a number is an Armstrong number in Java using digit extraction and power calculation with multiple approaches and examples.
+---
+
+An Armstrong number (also called a narcissistic number) is a number that equals the sum of its digits each raised to the power of the number of digits. For example:
+
+- 153 = 1³ + 5³ + 3³ = 1 + 125 + 27 = 153 (3 digits)
+- 9474 = 9⁴ + 4⁴ + 7⁴ + 4⁴ = 6561 + 256 + 2401 + 256 = 9474 (4 digits)
+
+Before you start, you may want to review:
+
+- [Java Variables and Literals](/docs/variables-and-literals)
+- [Java Operators](/docs/operators)
+- [Java Basic Input and Output](/docs/basic-input-output)
+
+## 1) Basic Armstrong Check
+
+This method extracts digits and calculates the sum of powers.
+
+### Example
+
+```java
+class Main {
+  public static void main(String[] args) {
+    int num = 153; // change value to test
+
+    if (isArmstrong(num)) {
+      System.out.println(num + " is an Armstrong number.");
+    } else {
+      System.out.println(num + " is not an Armstrong number.");
+    }
+  }
+
+  static boolean isArmstrong(int num) {
+    int original = num;
+    int digits = countDigits(num);
+    int sum = 0;
+
+    while (num > 0) {
+      int digit = num % 10;
+      sum += Math.pow(digit, digits);
+      num /= 10;
+    }
+
+    return original == sum;
+  }
+
+  static int countDigits(int num) {
+    if (num == 0) return 1;
+    int count = 0;
+    while (num > 0) {
+      count++;
+      num /= 10;
+    }
+    return count;
+  }
+}
+```
+
+#### Output (for num = 153)
+
+```plaintext
+153 is an Armstrong number.
+```
+
+## 2) Optimized Version (Without Math.pow)
+
+Avoid floating-point operations by using integer multiplication.
+
+### Example
+
+```java
+class Main {
+  public static void main(String[] args) {
+    int num = 9474; // change value to test
+
+    if (isArmstrongOptimized(num)) {
+      System.out.println(num + " is an Armstrong number.");
+    } else {
+      System.out.println(num + " is not an Armstrong number.");
+    }
+  }
+
+  static boolean isArmstrongOptimized(int num) {
+    int original = num;
+    int digits = countDigits(num);
+    int sum = 0;
+
+    while (num > 0) {
+      int digit = num % 10;
+      sum += power(digit, digits);
+      num /= 10;
+    }
+
+    return original == sum;
+  }
+
+  static int power(int base, int exp) {
+    int result = 1;
+    for (int i = 0; i < exp; i++) {
+      result *= base;
+    }
+    return result;
+  }
+
+  static int countDigits(int num) {
+    if (num == 0) return 1;
+    int count = 0;
+    while (num > 0) {
+      count++;
+      num /= 10;
+    }
+    return count;
+  }
+}
+```
+
+#### Output (for num = 9474)
+
+```plaintext
+9474 is an Armstrong number.
+```
+
+## 3) Find Armstrong Numbers in Range
+
+Program to find all Armstrong numbers within a given range.
+
+### Example
+
+```java
+import java.util.ArrayList;
+import java.util.List;
+
+class Main {
+  public static void main(String[] args) {
+    int start = 1;
+    int end = 10000;
+
+    System.out.println("Armstrong numbers between " + start + " and " + end + ":");
+    List<Integer> armstrongNumbers = findArmstrongInRange(start, end);
+
+    for (int num : armstrongNumbers) {
+      System.out.println(num + " (digits: " + countDigits(num) + ")");
+    }
+
+    System.out.println("\nTotal Armstrong numbers found: " + armstrongNumbers.size());
+  }
+
+  static List<Integer> findArmstrongInRange(int start, int end) {
+    List<Integer> result = new ArrayList<>();
+
+    for (int i = start; i <= end; i++) {
+      if (isArmstrong(i)) {
+        result.add(i);
+      }
+    }
+
+    return result;
+  }
+
+  static boolean isArmstrong(int num) {
+    int original = num;
+    int digits = countDigits(num);
+    int sum = 0;
+
+    while (num > 0) {
+      int digit = num % 10;
+      sum += power(digit, digits);
+      num /= 10;
+    }
+
+    return original == sum;
+  }
+
+  static int power(int base, int exp) {
+    int result = 1;
+    for (int i = 0; i < exp; i++) {
+      result *= base;
+    }
+    return result;
+  }
+
+  static int countDigits(int num) {
+    if (num == 0) return 1;
+    int count = 0;
+    while (num > 0) {
+      count++;
+      num /= 10;
+    }
+    return count;
+  }
+}
+```
+
+#### Sample Output
+
+```plaintext
+Armstrong numbers between 1 and 10000:
+1 (digits: 1)
+2 (digits: 1)
+3 (digits: 1)
+4 (digits: 1)
+5 (digits: 1)
+6 (digits: 1)
+7 (digits: 1)
+8 (digits: 1)
+9 (digits: 1)
+153 (digits: 3)
+371 (digits: 3)
+407 (digits: 3)
+1634 (digits: 4)
+8208 (digits: 4)
+9474 (digits: 4)
+
+Total Armstrong numbers found: 15
+```
+
+---
+
+### Notes & Tips
+
+- **Common Armstrong numbers**: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 371, 407, 1634, 8208, 9474
+- **Performance**: The optimized version using integer multiplication is faster than Math.pow()
+- **Large numbers**: For numbers with many digits, consider using `long` or `BigInteger` to avoid overflow
+- **Time complexity**: O(d) where d is the number of digits
+- **Space complexity**: O(1) for the basic check, O(n) for range finding
diff --git a/src/app/(site)/about/page.tsx b/src/app/(site)/about/page.tsx
@@ -142,8 +142,8 @@ export default function AboutPage() {
             >
               Our platform bridges complex Java concepts with real-world
               application through interactive tutorials, hands-on exercises, and
-              structured learning paths. Whether you&apos;re a complete beginner or
-              experienced developer, our community-driven approach ensures
+              structured learning paths. Whether you&apos;re a complete beginner
+              or experienced developer, our community-driven approach ensures
               accessible, practical learning for everyone.
             </motion.p>
           </div>

diff --git a/src/app/(site)/legal/privacy/page.tsx b/src/app/(site)/legal/privacy/page.tsx
@@ -21,10 +21,11 @@ export default function PrivacyPolicyPage(): React.ReactElement {
       <div className="prose prose-neutral dark:prose-invert max-w-none">
         <h2>1. Introduction</h2>
         <p>
-          Welcome to Javaistic (&quot;we,&quot; &quot;our,&quot; or &quot;us&quot;). We are committed to
-          protecting your privacy and ensuring transparency. This Privacy Policy
-          explains our practices regarding information handling on our open
-          source educational platform for learning Java programming.
+          Welcome to Javaistic (&quot;we,&quot; &quot;our,&quot; or
+          &quot;us&quot;). We are committed to protecting your privacy and
+          ensuring transparency. This Privacy Policy explains our practices
+          regarding information handling on our open source educational platform
+          for learning Java programming.
         </p>
         <p>
           <strong>Important:</strong> Javaistic does not require user accounts
@@ -69,8 +70,8 @@ export default function PrivacyPolicyPage(): React.ReactElement {
           If you choose to contribute to the Javaistic project through our
           public GitHub repository, any information you provide (such as GitHub
           username, email for commits, or pull request content) will be handled
-          according to GitHub&apos;s privacy policies and our open source licensing
-          terms.
+          according to GitHub&apos;s privacy policies and our open source
+          licensing terms.
         </p>
 
         <h2>4. How We Use Information</h2>
@@ -129,9 +130,9 @@ export default function PrivacyPolicyPage(): React.ReactElement {
         <p>
           Javaistic is an educational platform intended for learners of all ages
           interested in Java programming. Since we do not collect personal
-          information, there are no special considerations for children&apos;s data.
-          However, we recommend that children under 13 have parental guidance
-          when accessing technical content.
+          information, there are no special considerations for children&apos;s
+          data. However, we recommend that children under 13 have parental
+          guidance when accessing technical content.
         </p>
 
         <h2>8. International Users</h2>

diff --git a/src/app/(site)/legal/terms/page.tsx b/src/app/(site)/legal/terms/page.tsx
@@ -21,11 +21,12 @@ export default function TermsPage(): React.ReactElement {
       <div className="prose prose-neutral dark:prose-invert max-w-none">
         <h2>1. Acceptance of Terms</h2>
         <p>
-          By accessing and using Javaistic (&quot;the Platform,&quot; &quot;we,&quot; &quot;our,&quot; or
-          &quot;us&quot;), an open source educational platform for learning Java
-          programming, you accept and agree to be bound by the terms and
-          provision of this agreement (&quot;Terms of Service&quot; or &quot;Terms&quot;). If you do
-          not agree to abide by these terms, please do not use this platform.
+          By accessing and using Javaistic (&quot;the Platform,&quot;
+          &quot;we,&quot; &quot;our,&quot; or &quot;us&quot;), an open source
+          educational platform for learning Java programming, you accept and
+          agree to be bound by the terms and provision of this agreement
+          (&quot;Terms of Service&quot; or &quot;Terms&quot;). If you do not
+          agree to abide by these terms, please do not use this platform.
         </p>
 
         <h2>2. Description of Service</h2>
@@ -86,8 +87,8 @@ export default function TermsPage(): React.ReactElement {
           <li>Upload viruses, malware, or other harmful code</li>
           <li>
             Post content that is unlawful, harmful, threatening, abusive,
-            harassing, defamatory, vulgar, obscene, or invasive of another&apos;s
-            privacy
+            harassing, defamatory, vulgar, obscene, or invasive of
+            another&apos;s privacy
           </li>
           <li>
             Impersonate any person or entity or misrepresent your affiliation
@@ -97,9 +98,10 @@ export default function TermsPage(): React.ReactElement {
         <h3>4.2 Educational Use</h3>
         <p>
           The Platform is intended for educational purposes. While we strive to
-          provide accurate information, all content is provided &quot;as is&quot; for
-          learning purposes. Users should verify information independently and
-          use proper judgment when applying concepts learned here.
+          provide accurate information, all content is provided &quot;as
+          is&quot; for learning purposes. Users should verify information
+          independently and use proper judgment when applying concepts learned
+          here.
         </p>
 
         <h2>5. Content and Contributions</h2>
@@ -197,9 +199,10 @@ export default function TermsPage(): React.ReactElement {
         <h2>8. Disclaimers</h2>
         <h3>8.1 Service Availability</h3>
         <p>
-          The Platform is provided on an &quot;as is&quot; and &quot;as available&quot; basis. As an
-          open source project maintained by volunteers, we do not guarantee that
-          the Platform will be uninterrupted, timely, secure, or error-free.
+          The Platform is provided on an &quot;as is&quot; and &quot;as
+          available&quot; basis. As an open source project maintained by
+          volunteers, we do not guarantee that the Platform will be
+          uninterrupted, timely, secure, or error-free.
         </p>
 
         <h3>8.2 Educational Content</h3>

diff --git a/src/app/(site)/sponsors/page.tsx b/src/app/(site)/sponsors/page.tsx
@@ -261,8 +261,8 @@ export default function SponsorsPage() {
               <h3 className="text-lg font-semibold">Growing Platform</h3>
             </div>
             <p className="text-muted-foreground">
-              Support a platform that&apos;s helping developers learn and grow in the
-              Java ecosystem.
+              Support a platform that&apos;s helping developers learn and grow
+              in the Java ecosystem.
             </p>
             <div className="mt-3 text-xs font-medium text-purple-600 dark:text-purple-400">
               ✓ Growing platform reach