标签：bfs

Ignatius and the Princess I

5 6
.XX.1.
..X.2.
2...X.
...XX.
XXXXX.
5 6
.XX.1.
..X.2.
2...X.
...XX.
XXXXX1
5 6
.XX...
..XX1.
2...X.
...XX.
XXXXX.

It takes 13 seconds to reach the target position, let me show you the way.
1s:(0,0)->(1,0)
2s:(1,0)->(1,1)
3s:(1,1)->(2,1)
4s:(2,1)->(2,2)
5s:(2,2)->(2,3)
6s:(2,3)->(1,3)
7s:(1,3)->(1,4)
8s:FIGHT AT (1,4)
9s:FIGHT AT (1,4)
10s:(1,4)->(1,5)
11s:(1,5)->(2,5)
12s:(2,5)->(3,5)
13s:(3,5)->(4,5)
FINISH
It takes 14 seconds to reach the target position, let me show you the way.
1s:(0,0)->(1,0)
2s:(1,0)->(1,1)
3s:(1,1)->(2,1)
4s:(2,1)->(2,2)
5s:(2,2)->(2,3)
6s:(2,3)->(1,3)
7s:(1,3)->(1,4)
8s:FIGHT AT (1,4)
9s:FIGHT AT (1,4)
10s:(1,4)->(1,5)
11s:(1,5)->(2,5)
12s:(2,5)->(3,5)
13s:(3,5)->(4,5)
14s:FIGHT AT (4,5)
FINISH
God please help our poor hero.
FINISH

/*

起点(0,0)  终点(n-1,m-1),
  'x'代表不能走，
  '.'可以走，走过来需耗费一秒，
  数字代表可以走，不过走过来一秒还需要加上这个数字

优先队列，对于记录路径开一个path数组记录这一个点是从哪一个方向走来的就可以了，然后递归输出路径




*/


#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<set>
#include<map>

#define L(x) (x<<1)
#define R(x) (x<<1|1)
#define MID(x,y) ((x+y)>>1)

#define eps 1e-8
typedef __int64 ll;

#define fre(i,a,b)  for(i = a; i <b; i++)
#define free(i,b,a) for(i = b; i >= a;i--)
#define mem(t, v)   memset ((t) , v, sizeof(t))
#define ssf(n)      scanf("%s", n)
#define sf(n)       scanf("%d", &n)
#define sff(a,b)    scanf("%d %d", &a, &b)
#define sfff(a,b,c) scanf("%d %d %d", &a, &b, &c)
#define pf          printf
#define bug         pf("Hi\n")

using namespace std;

#define N 105



struct stud{
  stud(int xx,int yy,int s):x(xx),y(yy),step(s){};
  stud(){};
  int x,y,step;
  bool operator<(const stud b) const
  {
  	return step>b.step;
  }
};

int n,m;

priority_queue<stud>q;

int path[N][N];
int vis[N][N];
int step[4][2]={1,0,-1,0,0,1,0,-1};
int all;
char c[N][N];

bool judge(int x,int y)
{
	if(x>=0&&x<n&&y>=0&&y<m) return true;
	return false;
}

void show(int x,int y)
{
	if(x==0&&y==0) return ;
	int xx=x-step[path[x][y]][0];
	int yy=y-step[path[x][y]][1];
	show(xx,yy);
	printf("%ds:(%d,%d)->(%d,%d)\n",++all,xx,yy,x,y);

	if(c[x][y]>='0'&&c[x][y]<='9')
	{
		int i=c[x][y]-'0';
		while(i--)
			printf("%ds:FIGHT AT (%d,%d)\n",++all,x,y);
	}

}

bool bfs()
{
	int i,j;
	stud cur,next;
	while(!q.empty()) q.pop();
	mem(vis,0);
	vis[0][0]=1;
	cur.x=0;
	cur.y=0;
	cur.step=0;
	q.push(cur);
	while(!q.empty())
	{
		cur=q.top();
		q.pop();
		if(cur.x==n-1&&cur.y==m-1)
		{
		    printf("It takes %d seconds to reach the target position, let me show you the way.\n",cur.step);
		    all=0;
		    show(n-1,m-1);
		    return true;
		}

		for(i=0;i<4;i++)
		{
           int xx=cur.x+step[i][0];
           int yy=cur.y+step[i][1];
           if(!judge(xx,yy)) continue;
           if(vis[xx][yy]) continue;
           if(c[xx][yy]=='X') continue;

           next.x=xx;
           next.y=yy;
           next.step=cur.step+1;
           if(c[xx][yy]>='0'&&c[xx][yy]<='9')
		   next.step+=c[xx][yy]-'0';
           q.push(next);
           vis[xx][yy]=cur.step+1;
           path[xx][yy]=i;
		}
	}
  return false;
}

int main()
{
   int i,j;
   while(~scanf("%d%d",&n,&m))
   {
   	  for(i=0;i<n;i++)
		scanf("%s",c[i]);
	  if(!bfs()) printf("God please help our poor hero.\n");
	  printf("FINISH\n");
   }
   return 0;
}

/*



*/

HDU 1026 Ignatius and the Princess I（bfs +记录路径）

标签：bfs

原文地址：http://blog.csdn.net/u014737310/article/details/46763149