add: 完美数

src/math/perfect-number.js

@@ -0,0 +1,16 @@
+const pn = (p) => { // 欧几里得-欧拉定理
+  return (1 << (p - 1)) * ((1 << p) - 1)
+}
+
+/**
+ * @param {number} num
+ * @return {boolean}
+ */
+export const checkPerfectNumber = function (num) {
+  const primes = [2, 3, 5, 7, 13, 17, 19, 31]
+  for (const prime of primes) {
+    if (pn(prime) === num) return true
+  }
+
+  return false
+}