八皇后问题

注意主对角线和副对角线的判断

#include <stdio.h>
int pat[8][8] = {0};
int count = 0;

void findQueen(int row);
void printQueen();
bool check(int row,int column);

void findQueen(int row)
{
	if(row > 7)
	{
		count++;
		printQueen();
		return;
	}
	for(int column = 0;column < 8;column++)
	{
		if(check(row,column))
		{
			pat[row][column] = 1;
			findQueen(row+1);
			pat[row][column] = 0;//回退
		}
	}
}

void printQueen()
{
	for(int i = 0;i < 8;i++)
	{
		for(int j = 0;j < 8;j++)
			printf("%2d",pat[i][j]);
		printf("\n");
	}
	printf("\n");

}

bool check(int row,int column)
{
	//列
	for(int i = 0;i < row;i++)
	{
		if(pat[i][column] == 1)
			return false;
	}
	int j;
    i = row - 1;
	j = column - 1;
	//主对角线
	while(i >= 0 && j >= 0)
	{
    	if(pat[i][j] == 1)
			return false;
		i--;
		j--;
	}
	i = row - 1;
	j = column + 1;
	//负对角线
	while(i >= 0 && j < 8)
	{
    	if(pat[i][j] == 1)
			return false;
		i--;
		j++;
	}
	return true;
}



void main()
{
	findQueen(0);
	printf("%d\n",count);
}