HDU1372,BFS象棋马走日

简单的对于bfs的运用，但是还是写的太慢了写了TMD的1H，主要是不熟悉，以后慢慢熟悉就好了，模型基本已经能建立了，主要出现bug是在方向数组的运用上面，一定要记得是从0开始的，而不是从1开始的，导致错误。

#include<cstdio>
#include<cstdlib>
#include<iostream>

using namespace std;
/*bfs*/

//方向数组
int nextx[8][2]={
{-1,-2},
{-2,-1},
{1,2},
{2,1},
{1,-2},
{2,-1},
{-1,2},
{-2,1}
};

/*
1 0 3 0 5 6 7 8 9
0 2 3 4 0 6 7 8 9
1 2 0 4 5 6 7 8 9
0 2 3 4 0 6 7 8 9
1 0 3 0 5 6 7 8 9
1 2 3 4 5 6 7 8 9

*/

struct que
{
int x;//当前的A；
int y;//当前的B；
int step;//走过的步数
};

int main()
{
int i;//循环变量
int y1,y2;
int x1,x2;
int nowX,nowY;
char ch[10];

int head=1;
int tail=1;

struct que ques[100];

while (gets(ch) != NULL)
{
//将输入的数转换成对应数字
x1 = ch[0]-'a'+1;
y1 = ch[1]-'0';
x2 = ch[3]-'a'+1;
y2 = ch[4]-'0';

//初始化地图，用于记录走过的点
int maps[10][10]={0};

head=1;
tail=1;

maps[x1][y1] = 1;//记录初始点
ques[head].x = x1;
ques[head].y = y1;
ques[head].step = 0;

tail++;
nowX=x1;
nowY=y1;
if(nowX == x2 && nowY == y2)
{
goto f1;
}

while (head<tail)
{
for (i = 0; i < 8; i++)
{
nowX = ques[head].x + nextx[i][0];
nowY = ques[head].y + nextx[i][1];

if(nowX<=0 || nowX>8 || nowY<=0 || nowY>8)
continue;
if(maps[nowX][nowY] == 0)
{
maps[nowX][nowY] = 1;
ques[tail].x = nowX;
ques[tail].y = nowY;
ques[tail].step = ques[head].step + 1;
tail++;
}

if(nowX == x2 && nowY == y2)
{
goto f1;
}
}
head++;
}

f1:printf("To get from %c%d to %c%d takes %d knight moves.\n",ch[0],y1,ch[3],y2,ques[tail-1].step);
}
return 0;
}

/*

Sample Input

e2 e4
a1 b2
b2 c3
a1 h8
a1 h7
h8 a1
b1 c3
f6 f6

Sample Output

To get from e2 to e4 takes 2 knight moves.
To get from a1 to b2 takes 4 knight moves.
To get from b2 to c3 takes 2 knight moves.
To get from a1 to h8 takes 6 knight moves.
To get from a1 to h7 takes 5 knight moves.
To get from h8 to a1 takes 6 knight moves.
To get from b1 to c3 takes 1 knight moves.
To get from f6 to f6 takes 0 knight moves.

*/