标签：public tostring pre global == 博客 pos class return
看到八皇后问题的解决思路， 感觉很喜欢。 我用C#实现的版本之前贴在了百度百科上（https://baike.baidu.com/item/%E5%85%AB%E7%9A%87%E5%90%8E%E9%97%AE%E9%A2%98#2_7）。百度百科已经有Python版本， 且效率比我的高一点儿， 所以决定把我的版本在博客园贴出来。相信我的版本更容易理解。 希望能够对大家有所帮助。上代码：
Python:
# EightQueens.py
def checkConflict(queenList, nextY):
for posY in range(nextY):
if abs(queenList[posY]-queenList[nextY])==abs(posY-nextY) or queenList[posY] == queenList[nextY]:
return True
return False
count = 0
def putQueen(queenCount, queenList, nextY):
for queenList[nextY] in range(queenCount):
if checkConflict(queenList, nextY)==False:
nextY+=1
if nextY < queenCount:
putQueen(queenCount, queenList, nextY)
else:
global count
count+=1
print(str(count)+": " + ", ".join(str(pos) for pos in queenList))
nextY-=1
# call the method
queenCount = 12
queenList = [0] * queenCount
putQueen(queenCount, queenList, 0)
C#:
// EightQueens.cs
namespace EightQueens
{
class EightQueens
{
private bool checkConflict(List<int> queenList, int nextY)
{
for (int positionY = 0; positionY < nextY; positionY++)
{
if (Math.Abs(queenList[positionY] - queenList[nextY]) == Math.Abs(positionY - nextY) || queenList[positionY] == queenList[nextY])
{
return true;
}
}
return false;
}
long count = 0;
public void putQueen(int queenCount, List<int> queenList, int nextY)
{
for (queenList[nextY] = 0; queenList[nextY] < queenCount; queenList[nextY]++)
{
if (checkConflict(queenList, nextY) == false)
{
nextY++;
if (nextY < queenCount)
{
putQueen(queenCount, queenList, nextY);
}
else
{
count++;
Console.WriteLine(count.ToString() + ": " + string.Join(", ", queenList));
}
nextY--;
}
}
}
}
}
方法调用：
// Program.cs
namespace EightQueens
{
class Program
{
static void Main(string[] args)
{
int queenCount = 12;
List<int> queenList = new List<int>();
for (int i = 0; i < queenCount; i++)
{
queenList.Add(0);
}
new EightQueens().putQueen(queenCount, queenList, 0);
Console.ReadKey();
}
}
}
当Queen的数量越多， 可以看到Python和C#的效率差别越大。
标签：public tostring pre global == 博客 pos class return
原文地址：https://www.cnblogs.com/Freeway/p/eightqueens.html
