摘要：
N-Queens II (H) 题目 The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other. Given an int 阅读全文
摘要：
N-Queens (H) 题目 The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other. Given an intege 阅读全文
摘要：
Arranging Coins (E) 题目 You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins. Given n 阅读全文