POJ - 3984 迷宫问题 （BFS+前缀处理输出路径）

#include<cstdio>
#include<stdio.h>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
#define INF 0x3f3f3f3f
#define MAX 1005

using namespace std;

int Map[MAX][MAX],n,v[4][2]= {{0,1},{0,-1},{1,0},{-1,0}};

struct node
{
int x,y,step;
} ans[MAX][MAX];

void DFS(int x,int y)
{
if(x==0&&y==0)
return ;

Ans(ans[x][y].x,ans[x][y].y);
printf("(%d, %d)\n",x,y);
}

void BFS()
{
queue<node>Q;
node a,next;
a.x=0;
a.y=0;
a.step=0;
Q.push(a);
Map[0][0]=1;

while(!Q.empty())
{
a=Q.front();
Q.pop();

if(a.x==4 && a.y==4)
{
printf("(0, 0)\n");
Ans(4,4);
return;
}

for(int i=0; i<4; i++)
{
next.x=a.x+v[i][0];
next.y=a.y+v[i][1];

if(next.x>=0 && next.x<5 && next.y>=0 && next.y<5 && Map[next.x][next.y]==0)
{
Map[next.x][next.y]=1;
next.step=a.step+1;

ans[next.x][next.y].x=a.x;//记录上一个点
ans[next.x][next.y].y=a.y;
Q.push(next);
}
}
}
}

int main()
{
int i,j;

for(i=0; i<5; i++)
for(j=0; j<5; j++)
scanf("%d",&Map[i][j]);

BFS();

return 0;
}

<pre name="code" class="cpp">#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
int map[6][6];
int book[6][6];
int ds[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
struct node
{
int s,y;
}point[6][6];
int judge(int a,int b)
{
if(a>=1&&a<=5&&b>=1&&b<=5)
return 1;
return 0;
}
void dfs(int s,int y)
{
if(s==1&&y==1)
return ;
dfs(point[s][y].s,point[s][y].y);
printf("(%d, %d)\n",s-1,y-1);
}
int bfs(int a,int b)
{
book[a][b]=1;
queue<node>Q;
node temp1;
temp1.s=a;
temp1.y=b;
Q.push(temp1);
while(!Q.empty())
{
node temp2=Q.front();
Q.pop();
if(temp2.s==5&&temp2.y==5)
{
printf("(0, 0)\n");
dfs(point[5][5].s,point[5][5].y);
printf("(4, 4)\n");
return 0;
}
for(int i=0;i<4;i++)
{
temp1.s=temp2.s+ds[i];
temp1.y=temp2.y+dy[i];
if(judge(temp1.s,temp1.y)&&map[temp1.s][temp1.y]==0)
{
if(book[temp1.s][temp1.y]==0)
{
//printf("1");
book[temp1.s][temp1.y]=1;
point[temp1.s][temp1.y].s=temp2.s;
point[temp1.s][temp1.y].y=temp2.y;
Q.push(temp1);
}
}
}
}
}

int main()
{
for(int i=1;i<=5;i++)
{
for(int j=1;j<=5;j++)
{
scanf("%d",&map[i][j]);
}
}
bfs(1,1);
}

div class="plm" style="text-align: center; font-size: 12pt; color: rgb(34, 34, 34); clear: both;"><div class="ptt" id="problem_title" style="font-size: 18pt; font-weight: bold; color: blue; padding: 10px;"><span style="color: green;">- </span>迷宫问题</div><span id="crawlSuccess" class="crawlInfo" style="display: inline;"><strong>Time Limit:</strong><span id="timeLimit">1000</span>MS     <strong>Memory Limit:</strong><span id="memoryLimit">65536</span>KB     <strong>64bit IO Format:</strong><span id="_64IOFormat">%I64d & %I64u</span></span><div id="problem_opt" style="font-size: 12px; margin-top: 10px;"><a target=_blank id="submit" class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" role="button" style="display: inline-block; position: relative; padding: 0px; margin-right: 0.1em; cursor: pointer; vertical-align: middle; overflow: visible; font-family: Verdana, Arial, sans-serif; font-size: 1em; border: 1px solid rgb(211, 211, 211); color: rgb(85, 85, 85); border-radius: 4px; background: url("../jquery-ui-1.11.1.custom/images/ui-bg_glass_75_e3e4f8_1x400.png") 50% 50% repeat-x rgb(227, 228, 248);"><span class="ui-button-text" style="display: block; padding: 0.4em 1em;">Submit</span></a> <a target=_blank id="problem_status" href="http://acm.hust.edu.cn/vjudge/contest/122002#status//N/0" class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" role="button" style="display: inline-block; position: relative; padding: 0px; margin-right: 0.1em; cursor: pointer; vertical-align: middle; overflow: visible; text-decoration: none; font-family: Verdana, Arial, sans-serif; font-size: 1em; border: 1px solid rgb(211, 211, 211); color: rgb(85, 85, 85); border-radius: 4px; background: url("../jquery-ui-1.11.1.custom/images/ui-bg_glass_75_e3e4f8_1x400.png") 50% 50% repeat-x rgb(227, 228, 248);"><span class="ui-button-text" style="display: block; padding: 0.4em 1em;">Status</span></a></div></div><div style="color: rgb(34, 34, 34); font-family: Verdana, Arial, sans-serif; font-size: 14px; width: 960px; margin: auto;"><div class="hiddable" id="vj_description" style="font-family: "times new roman"; font-size: 17px;"><p class="pst" style="font-family: Arial, Helvetica, sans-serif; font-size: 18pt; font-weight: bold; color: blue; margin-bottom: 0px;">Description</p><div class="textBG" style="border-radius: 10px; padding: 10px; border-style: dotted; border-width: 2px; background-color: rgb(234, 235, 255);"><div class="ptx" lang="en-US" style="font-family: "Times New Roman", Times, serif; font-size: 12pt;">定义一个二维数组： 
<pre style="white-space: pre-wrap; word-wrap: break-word;">int maze[5][5] = {

0, 1, 0, 0, 0,

0, 1, 0, 1, 0,

0, 0, 0, 0, 0,

0, 1, 1, 1, 0,

0, 0, 0, 1, 0,

};

它表示一个迷宫，其中的1表示墙壁，0表示可以走的路，只能横着走或竖着走，不能斜着走，要求编程序找出从左上角到右下角的最短路线。

Input

一个5 × 5的二维数组，表示一个迷宫。数据保证有唯一解。

Output

左上角到右下角的最短路径，格式如样例所示。

Sample Input

0 1 0 0 0
0 1 0 1 0
0 0 0 0 0
0 1 1 1 0
0 0 0 1 0

Sample Output

(0, 0)
(1, 0)
(2, 0)
(2, 1)
(2, 2)
(2, 3)
(2, 4)
(3, 4)
(4, 4)