OJ-Problems-Source/HDOJ/1484_autoAC.cpp

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <stack>
using namespace std;
const int MAX = 9,limit = 6,INF = 1000;
const int dirx[4]={0,-1,0,1},diry[4]={1,0,-1,0};
int map[MAX][MAX][4];
int dist[MAX][MAX],pre[MAX][MAX][2];
int sx,sy,ex,ey,pax,pay,pbx,pby;
stack<char> st;
void init(){
    int i,j;
    for(i=0;i<MAX;++i){
        for(j=0;j<MAX;++j){
            dist[i][j] = INF;
            map[i][j][0] = map[i][j][1] = map[i][j][2] = map[i][j][3] = 0;
        }
    }
}
void dfs(int x,int y,int cnt){
    int i,tx,ty;
    for(i=0;i<4;++i){
        if(map[x][y][i]==1)continue;
        tx = x+dirx[i];
        ty = y+diry[i];
        if(tx<1 || ty<1 || tx>limit || ty>limit)continue;
        if(cnt+1>dist[tx][ty])continue;
        dist[tx][ty] = cnt;
        pre[tx][ty][0] = x;
        pre[tx][ty][1] = y;
        dfs(tx,ty,cnt+1);
    }
}
void Path(){
    int px,py,x,y;
    x = ex,y = ey;
    px = pre[x][y][0];
    py = pre[x][y][1];
    while(1){
        if(x==px){
            if(py<y)st.push('E');
            else st.push('W');
        }else{
            if(px<x)st.push('S');
            else st.push('N');
        }
        if(px==sx && py==sy)break;
        x = px;
        y = py;
        px = pre[x][y][0];
        py = pre[x][y][1];
    }
    while(!st.empty()){
        printf("%c",st.top());
        st.pop();
    }
    printf("\n");
}
int main(){
    int i,j;
    while(scanf("%d %d",&sy,&sx)){
        if(sx==0 && sy==0)break;
        scanf("%d %d",&ey,&ex);
        init();
        for(i=0;i<3;++i){
            scanf("%d %d %d %d",&pay,&pax,&pby,&pbx);
            if(pax==pbx){
                for(j=pay+1;j<=pby;++j){
                    map[pax][j][3] = 1;
                    map[pax+1][j][1] = 1;
                }
            }else{
                for(j=pax+1;j<=pbx;++j){
                    map[j][pby][0] = 1;
                    map[j][pby+1][2] = 1;
                }
            }
        }
        dfs(sx,sy,0);
        Path();
    }
    return 0;
}