标签：dfs   hdu   

N皇后问题

1
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1
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#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>

using namespace std;

const int MAX = 15;

bool col[MAX+1],lx[MAX],ly[MAX];

int ans[MAX] = {0,1,0,0,2,10,4,40,92,352,724};



void dfs(int x,int limit){
	int i;

	if(x>limit){
		++ans[limit];
		return;
	}
	for(i=1;i<=limit;++i){		
		if(col[i])continue;
		if(lx[x-i+limit-1])continue;
		if(ly[x+i])continue;
		lx[x-i+limit-1] = true;
		ly[x+i] = true;
		col[i] = true;
		dfs(x+1,limit);
		col[i] = false;
		lx[x-i+limit-1] = false;
		ly[x+i] = false;
	}
}

void init(){
	int i;

	for(i=1;i<=MAX;++i){
		col[i] = false;
		lx[MAX] = false;
		ly[MAX] = false;
		ans[i] = 0;
	}

	for(i=1;i<=10;++i){
		dfs(1,i);
	}
}

int main(){
    //freopen("in.txt","r",stdin);
    //(author : CSDN iaccepted)
	//init();

	int n;

	while(scanf("%d",&n)){
		if(n==0)break;
		printf("%d\n",ans[n]);
	}
    return 0;
}

HDU 2553 N皇后问题 (搜索DFS),布布扣,bubuko.com

HDU 2553 N皇后问题 (搜索DFS)

标签：dfs   hdu   

原文地址：http://blog.csdn.net/iaccepted/article/details/26172471