lettuan

摘要： Given a 2D board containing 'X' and 'O' (the letter O), capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in 阅读全文

摘要： There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it cost 阅读全文

摘要： Keys: 在一个list中根据index可以同时去掉多个element, see L21 阅读全文

摘要： Given 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 connecting adjacen 阅读全文