主要是题意有点不好理解
题目大意:给你副图 有点个出口 问从这两出口中一进一出(比如出口A,B 可以从A进去B出去走一遍,再从B进去A出来走一遍)
能走的条件为:第一不能有墙,第二,能往右走往右走,不然往前走,再不行就往左走,最后再往后走,问最终能否走遍图中全部格子。
起初不懂怎么存储原图,还是新大神指点迷津
递归DFS会爆栈
#include<stdio.h>
#include<iostream>
#include<string>
#include<string.h>
#include<math.h>
#include<algorithm>
#include<vector>
#include<queue>
using namespace std;
const int maxn = 605;
const int inf = 1<<30;
int n,m,ans;
int xs[] = {0,-1,0,1}; //右上左下
int ys[] = {1,0,-1,0};
int r = 0,u = 1,l = 2,d = 3;
struct node
{
bool wall[4];
}map[maxn][maxn];
bool vis[maxn][maxn];
void DFS( int x,int y,int dir )
{
int d;
while( 1 ){
if( flag || x < 0 || x >= n )
break;
vis[x][y] = true;
for( int i = -1;i <= 2; i ++ ){
d = (dir+i+4)%4;
if( map[x][y].wall[d] ){
x+=xs[d];y+=ys[d];dir = d;
break;
}
}
}
}
void fun()
{
for( int i = 0; i < n; i ++ )
for( int j = 0; j < m; j ++ )
if( !vis[i][j] ){
puts("NO");
return;
}
puts("YES");
}
void init()
{
memset(vis,0,sizeof(vis));
for( int i = 0; i <= n; i ++ )
for( int j = 0; j <= m; j ++ )
for( int k = 0; k < 4; k ++ )
map[i][j].wall[k] = 0;
}
int main()
{
//freopen("data.txt","r",stdin);
int cas,s,e,temp;
scanf("%d",&cas);
while( cas -- )
{
scanf("%d%d%d%d",&n,&m,&s,&e);
init();
for( int i = 0; i < n-1; i ++ ){
for( int j = 0; j < m-1; j ++ ){
scanf("%d",&temp);
if( temp )
map[i][j].wall[r] = map[i][j+1].wall[l] = 0;
else
map[i][j].wall[r] = map[i][j+1].wall[l] = 1;
}
for( int j = 0; j < m; j ++ ){
scanf("%d",&temp);
if( temp )
map[i][j].wall[d] = map[i+1][j].wall[u] = 0;
else
map[i][j].wall[d] = map[i+1][j].wall[u] = 1;
}
}
for( int j = 0; j < m-1; j ++ ){
scanf("%d",&temp);
if( temp )
map[n-1][j].wall[r] = map[n-1][j+1].wall[l] = 0;
else
map[n-1][j].wall[r] = map[n-1][j+1].wall[l] = 1;
}
map[0][s].wall[u] = 1;
map[n-1][e].wall[d] = 1;
DFS( 0,s,d );
DFS( n-1,e,u);
fun();
}
return 0;
}