dfs模版

dfs

#include <stdio.h>

#include <string.h>

char Map[16][16];

int mv[16][16];

//mv[i][j] == 0 没有被访问

//mv[i][j] == 1 已经被访问

struct N

{

int x,y;

} ;

int jx[] = { 0,-1, 0, 1};

int jy[] = { 1, 0,-1, 0};

int Min;

void dfs(int x,int y,int n,int m,int ans)

{

if(ans >= Min)

{

return ;

}

if(Map[x][y] == 'Y')

{

if(ans < Min)

{

Min = ans;

}

return ;

}

N f;

for(int i = 0; i < 4; ++i)

{

f.x = x + jx[i];

f.y = y + jy[i];

if(0 <= f.x && f.x < n && 0 <= f.y && f.y < m && mv[f.x][f.y] == 0 && Map[f.x][f.y] != '#')

{

mv[f.x][f.y] = 1;

dfs(f.x,f.y,n,m,ans+1);

mv[f.x][f.y] = 0;

}

}

}

int main()

{

int n,m,i,j;

while(scanf("%d %d",&n,&m) != EOF)

{

memset(mv,0,sizeof(mv));

for(i = 0; i < n; ++i)

{

scanf("%*c%s",Map[i]);

}

for(i = 0; i < n; ++i)

{

for(j = 0; j < m; ++j)

{

if(Map[i][j] == 'X')

break;

}

if(j != m)

break;

}

Min = (1<<20);

dfs(i,j,n,m,0);

if(Min == (1<<20))

{

printf("-1\n");

}

else

{

printf("%d\n",Min);

}

}

return 0;

}