模板，BFS

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#include <stdio.h>#include <string.h>#include <queue>using namespace std;struct node{    int x,y,step;};char map[105][105];int vis[105][105];int to[4][2]= {1,0,-1,0,0,1,0,-1};int n,m,sx,sy,ex,ey,ans;int check(int x,int y){    if(x<0 || x>=n || y<0 || y>=m)        return 1;    if(vis[x][y] || map[x][y]=='#')        return 1;    return 0;}void bfs(){    int i;    queue<node> Q;    node a,next;    a.x = sx;    a.y = sy;    a.step = 0;    vis[a.x][a.y]=1;    Q.push(a);    while(!Q.empty())    {        a = Q.front();        Q.pop();        if(map[a.x][a.y]=='E')        {            ans = a.step;            return ;        }        for(i = 0; i<4; i++)        {            next = a;            next.x+=to[i][0];            next.y+=to[i][1];            if(check(next.x,next.y))                continue;            next.step=a.step+1;            vis[next.x][next.y] = 1;            Q.push(next);        }    }    ans = -1;}int main(){    int t;    scanf("%d",&t);    while(t--)    {        scanf("%d%d",&n,&m);        int i,j;        for(i = 0; i<n; i++)            scanf("%s",map[i]);        for(i = 0; i<n; i++)        {            for(j = 0; j<m; j++)            {                if(map[i][j]=='S')                {                    sx = i;                    sy = j;                }            }        }        memset(vis,0,sizeof(vis));        bfs();        printf("%d\n",ans);    }    return 0;}
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