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src/factorial.js

@@ -1,5 +1,12 @@
 const factorial = (number) => {
   // your code here
+  if (number < 0) throw new Error("Entrada no válida");
+
+  result = 1;
+
+  for (let i = number; i > 1; i--) result *= i;
+
+  return result;
 }
 
 module.exports = factorial;

src/fibonacci.js

@@ -1,5 +1,17 @@
 const fibonacci = (n) => {
   // your code here
+  // 0 1 1 2 3 5 8
+  let a = 0, b = 1;
+  const fibonacciSerie = [];
+
+  for (let i = 1; i <= n; i++) {
+    fibonacciSerie.push(b);
+    const aux = a;
+    a = b;
+    b = aux + b;
+  }
+
+  return fibonacciSerie;
 }
 
 module.exports = fibonacci;

src/primalidad.js

@@ -1,5 +1,13 @@
 const trialDivision = (number) => {
   // your code here
+  if (number !== Math.round(number)) return false;
+
+  const divisores = [];
+  for (let i = 2; i < 10; i++)
+    if (i !== number && number % i === 0) divisores.push(i);
+
+  // console.log(divisores);
+  return number > 1 && divisores.length === 0;
 }
 
 module.exports = trialDivision;