4038: Robot Navigation --bfs(求最短路及其路径条数）

#include<bits/stdc++.h>
using namespace std;
#define MOD 1000000
char mp[105][105];
int ans[105][105][6],visit[105][105][6],step[105][105][6];
int dx[]={-1,0,1,0};
int dy[]={0,1,0,-1};
struct node{
    int x,y,f,st;
}s,e,q,p;
int flag,n,m;
int check()//转弯
{
    if(visit[q.x][q.y][q.f]==1){
        if(step[q.x][q.y][q.f]==p.st+1)ans[q.x][q.y][q.f]=(ans[p.x][p.y][p.f]+ans[q.x][q.y][q.f])%MOD;
        return 0;
    }
    else{
        visit[q.x][q.y][q.f]=1;
        ans[q.x][q.y][q.f]=ans[p.x][p.y][p.f];
        q.st=p.st+1;
        step[q.x][q.y][q.f]=q.st;
        return 1;
    }
}
int check2()//直行
{
    if(q.x<0||q.x>=n||q.y<0||q.y>=m||mp[q.x][q.y]==‘*‘)return 0;
    if(visit[q.x][q.y][q.f]==1){
        if(step[q.x][q.y][q.f]==p.st+1)ans[q.x][q.y][q.f]=(ans[p.x][p.y][p.f]+ans[q.x][q.y][q.f])%MOD;
        return 1;
    }
    else{
        visit[q.x][q.y][q.f]=1;
        ans[q.x][q.y][q.f]=ans[p.x][p.y][p.f];
        q.st=p.st+1;
        step[q.x][q.y][q.f]=q.st;
        return 2;
    }
}
void bfs()
{
    int i;
    if(e.x==s.x&&e.y==s.y){
        printf("0 1\n");
        return;
    }
    memset(visit,0,sizeof visit);
    memset(ans,0,sizeof ans);
    memset(step,0x3f3f3f3f,sizeof step);
    flag=0;
    queue<node>qu;
    qu.push(s);
    ans[s.x][s.y][s.f]=1;
    visit[s.x][s.y][s.f]=1;
    while(!qu.empty()){
        p=qu.front();qu.pop();
       // cout<<"ppp"<<p.x<<p.y<<" "<<p.f<<‘ ‘<<p.st<<"ans"<<ans[p.x][p.y][p.f]<<endl;
        if(p.x==e.x&&p.y==e.y){
            flag=1;
            step[p.x][p.y][p.f]=p.st;
            continue;
        }
        node n1=p;
        while(1){
            q.x=n1.x+dx[p.f];q.y=n1.y+dy[p.f];q.f=p.f;
            n1.x=q.x,n1.y=q.y;
            int ii=check2();
            if(ii==0)break;
           // cout<<q.x<<"x-y"<<q.y<<" "<<q.st<<endl;
            else if(ii==2)qu.push(q);
        }
        q.x=p.x;q.y=p.y;q.f=(p.f+1)%4;
        if(check())qu.push(q);
        q.x=p.x;q.y=p.y;q.f=(p.f+3)%4;
        if(check())qu.push(q);
    }
    if(flag==0){
        printf("0 0\n");
        return;
    }
    int minn=0x3f3f3f3f,sum=0;
    for(i=0;i<4;i++)minn=min(minn,step[e.x][e.y][i]);
    for(i=0;i<4;i++){
        if(step[e.x][e.y][i]==minn)sum=(sum+ans[e.x][e.y][i])%MOD;
    }
    printf("%d %d\n",minn,sum);
}
int main()
{
    int i,j;
    while(scanf("%d%d",&n,&m),n!=0||m!=0){
        getchar();
        for(i=0;i<n;i++){
            for(j=0;j<m;j++){
                scanf("%c",&mp[i][j]);
                if(mp[i][j]==‘X‘)e.x=i,e.y=j;
                else if(mp[i][j]>=‘A‘&&mp[i][j]<=‘Z‘){
                    s.x=i,s.y=j;
                    s.st=0;
                    if(mp[i][j]==‘N‘)s.f=0;
                    else if(mp[i][j]==‘S‘)s.f=2;
                    else if(mp[i][j]==‘W‘)s.f=3;
                    else s.f=1;
                }
            }
            getchar();
        }
        bfs();
    }
    return 0;
}