lingen1949的专栏

382. Linked List Random Node Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen. Follow up: What if the li

406. Queue Reconstruction by Height

404. Sum of Left Leaves Find the sum of all left leaves in a given binary tree. Example: 3 / \ 9 20 / \ 15 7 There are two left leaves in the binary tree, with values 9 and

421. Maximum XOR of Two Numbers in an Array Given a non-empty array of numbers, a0, a1, a2, … , an-1, where 0 ≤ ai < 231. Find the maximum result of ai XOR aj, where 0 ≤ i, j n. Cou