摘要：
Binary Tree Right Side ViewGiven a binary tree, imagine yourself standing on therightside of it, return the values of the nodes you can see ordered fr... 阅读全文
摘要：
Number of IslandsGiven a 2d grid map of'1's (land) and'0's (water), count the number of islands. An island is surrounded by water and is formed by con... 阅读全文