πΆ Is it just my device?
Using a single SIM or two SIMs from the same provider gives me slower speeds. But with two different providers, network speed suddenly improves. π€
#DualSIM#NetworkSpeed
Day 100β
Valid BST βοΈ
Use DFS + range check
Each node must lie in (min, max)
Left β (min, val), Right β (val, max)
If violated β β
Time: O(n) | Space: O(h)
#DSA#Java#LeetCode