Create 367-valid-perfect-square.js

Author: everthis

367-valid-perfect-square.js

@@ -0,0 +1,25 @@
+/**
+ * @param {number} num
+ * @return {boolean}
+ */
+
+const isPerfectSquare = function(num) {
+    let lo = 1
+    let hi = num
+    let mid
+    let val
+    while(lo <= hi) {
+        mid = (lo + hi) >>> 1
+        val = mid * mid
+        if (val === num) {
+            return true
+        }
+        if (val < num) {
+            lo = mid + 1
+        }
+        if (val > num) {
+            hi = mid - 1
+        }
+    }
+    return false
+};