projEuler3.ts

inputs/passing/projEuler3.ts

@@ -0,0 +1,50 @@
+export default function main() {
+  return factorize(600851475143);
+}
+
+function factorize(n: number): number[] {
+  let factors: number[] = [];
+  let p = 2;
+
+  while (true) {
+    while (n % p === 0) {
+      factors.push(p);
+      n /= p;
+    }
+
+    if (n === 1) {
+      return factors;
+    }
+
+    p = nextOddPrime(p);
+
+    if (p * p > n) {
+      factors.push(n);
+      return factors;
+    }
+  }
+}
+
+function nextOddPrime(n: number): number {
+  n += 1 + (n % 2); // Next odd number
+
+  while (!isOddPrime(n)) {
+    n += 2;
+  }
+
+  return n;
+}
+
+function isOddPrime(n: number): boolean {
+  let i = 3;
+
+  while (i * i <= n) {
+    if (n % i === 0) {
+      return false;
+    }
+
+    i += 2;
+  }
+
+  return true;
+}