Create 0069-sqrtx.js

Solved sqrtx in JS.

Author: aadil42

javascript/0069-sqrtx.js

@@ -0,0 +1,24 @@
+/**
+ * Binary Search 
+ * https://leetcode.com/problems/sqrtx/
+ * 
+ * Time O(log(n)) | Space O(1)
+ * @param {number} x
+ * @return {number}
+ */
+var mySqrt = function(x) {
+    let left = 1;
+    let right = x;
+ 
+    while(left <= right) {
+        const mid = left + Math.floor((right - left)/2);
+        if(mid * mid <= x && (mid+1) * (mid+1) > x) return mid;
+        if(mid * mid < x) {
+            left = mid + 1;
+        } else {
+            right = mid -1;
+        }
+    } 
+ 
+    return 0;
+ };