Data update

Task/Cuban-primes/JavaScript/cuban-primes.js

@@ -0,0 +1,68 @@
+const MAX = 1400000;
+const primes = new Array(MAX);
+
+function preCompute() {
+    // Initialize sieve
+    for (let i = 2; i < MAX; i++) {
+        primes[i] = true;
+    }
+
+    // Sieve of Eratosthenes
+    for (let i = 2; i < MAX; i++) {
+        if (primes[i]) {
+            for (let j = 2 * i; j < MAX; j += i) {
+                primes[j] = false;
+            }
+        }
+    }
+}
+
+function isPrime(n) {
+    if (n < MAX) {
+        return primes[n];
+    }
+    const max = Math.floor(Math.sqrt(n));
+    for (let i = 3; i <= max; i++) {
+        if (primes[i] && n % i === 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+function cubanPrime(n, display) {
+    let count = 0;
+    let result = 0;
+    let output = '';
+
+    for (let i = 0; count < n; i++) {
+        const test = 1 + 3 * i * (i + 1);
+        if (isPrime(test)) {
+            count++;
+            result = test;
+            if (display) {
+                const formatted = test.toLocaleString('en-US').padStart(10);
+                output += formatted + (count % 10 === 0 ? '\n' : '');
+            }
+        }
+    }
+
+    if (display) {
+        console.log(output);
+    }
+    return result;
+}
+
+// Main execution
+preCompute();
+
+// First 200 Cuban primes
+cubanPrime(200, true);
+console.log();
+
+// Specific Cuban primes
+for (let i = 1; i <= 5; i++) {
+    const max = Math.pow(10, i);
+    const prime = cubanPrime(max, false);
+    console.log(`${max.toLocaleString('en-US')}-th cuban prime = ${prime.toLocaleString('en-US')}`);
+}