摘要：
Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following rules: Empty cells are indica 阅读全文
摘要：
Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules: A partially filled sudoku which 阅读全文
摘要：
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 integer n, return the 阅读全文
摘要：
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 integer n, return all 阅读全文