Create 0367-valid-perfect-square.kt

Author: a93a

kotlin/0367-valid-perfect-square.kt

@@ -0,0 +1,16 @@
+class Solution {
+    fun isPerfectSquare(num: Int): Boolean {
+        var l = 1L
+        var r = num.toLong()
+        while (l <= r) {
+            val m = (l + r) / 2
+            if (m * m > num)
+                r = m - 1
+            else if (m * m < num)
+                l = m + 1
+            else
+                return true
+        }
+        return false
+    }
+}