60分求助
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60分求助
525998
huangjiasheng楼主2022/8/1 19:37
#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <math.h>
#include <queue>
#include <stack>
#include <string.h>
using namespace std;
const int N = 1e5 + 10;
int a[100][100];
bool flag(int num)
{
	if(num < 2) return false;
	if(num == 2) return true;
	if(num%2 == 0) return false;
	for(int i = 3 ; i*i <= num ; i+= 2)
		if(num %i == 0) 
			return false;
	return true;
}
int n;
void calc(int id , int &x , int &y)
{
	if(id < n)
		x = 0 , y = id;
	else if(id < 2*n- 1)
	{
		y = 0;
		x = id - n + 1;
	}
	else 
	{
		id = id - 2*n + 1;
		x = id/(n-1);
		y = id%(n-1);
		x++;
		y++;
	}
}
int dx[] = {1,-1,0 ,0};
int dy[] = {0,0,1,-1};
int vis[N];
bool find(int id , int num)
{
	int x,y;
	calc(id , x ,y);
	for(int i = 0 ; i < 4 ; i++)
	{
		int xx = x + dx[i];
		int yy = y + dy[i];
		if(xx < 0 || yy < 0 || xx >= n || yy >= n || a[xx][yy] == -1)
			continue;
		if( !flag( a[xx][yy] + num ) )
			return false;
	}
	return true;
}
void dfs(int id)
{	
	int x,y;
	calc(id , x ,y);
//	cout << x << " " << y << " " << id << endl;
	if(id == n*n)
	{
		for(int i = 0; i < n ; i++)
		{
			for(int j= 0; j < n ; j++)
				cout << a[i][j] << " ";
			cout << endl;
		}
		exit(0);
	}
	for(int i = 1 ; i <= n*n ; i++)
	{
		if(vis[i]) continue;
		if(!find(id , i)) continue;
		vis[i] = 1;
		a[x][y] = i;
		dfs(id + 1);
		vis[i] = 0;
		a[x][y] = -1;
	}
	
}
int main()
{
	memset(a,-1,sizeof a);
	cin >> n;
	a[0][0] = 1;
	vis[1] = 1;
	if(n != 1)
		dfs(1);
	cout << "NO";
}

2022/8/1 19:37
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