POJ 3083 Children of the Candy Corn

阅读理解题。。。。。。

题目很简单，让你顺时针方向DFS一次求路径长，逆时针方向DFS一次求路径长，在BFS一下求最短路径。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <queue>
using namespace std;
int w,h,map[50][50];
struct coordinate
{
    int x;
    int y;
};
coordinate s,e;
bool judge(coordinate a)
{
    if (a.x < 0 || a.x >= h || a.y < 0 || a.y >= w)
        return false;
    if (map[a.x][a.y] == 8)
        return false;
    return true;
}
int dir_right[4][2]={{0,-1},{1,0},{0,1},{-1,0}},dr;
int dir_left[4][2]={{0,1},{1,0},{0,-1},{-1,0}},dl;
int DFS_Right(coordinate t,int cnt)
{
    if (t.x == e.x && t.y == e.y)
        return cnt;
    coordinate tc;
    int i,j;
    dr+=3;
    dr%=4;
    for (i=0; i<4; i++)
    {
        tc.x=t.x+dir_right[dr][0];
        tc.y=t.y+dir_right[dr][1];
        if (judge(tc))
        {
            j=DFS_Right(tc,cnt+1);
            if (j != 0)
                return j;
        }
        dr++;
        dr%=4;
    }
}
int DFS_Left(coordinate t,int cnt)
{
    if (t.x == e.x && t.y == e.y)
        return cnt;
    coordinate tc;
    int i,j;
    dl+=3;
    dl%=4;
    for (i=0; i<4; i++)
    {
        tc.x=t.x+dir_left[dl][0];
        tc.y=t.y+dir_left[dl][1];
        if (judge(tc))
        {
            j=DFS_Left(tc,cnt+1);
            if (j != 0)
                return j;
        }
        dl++;
        dl%=4;
    }

}
int v[50][50];
void BFS()
{
    coordinate tc,ttc;
    int i;
    queue<coordinate> q;
    while (!q.empty())
        q.pop();
    q.push(s);
    v[s.x][s.y]=1;
    while (!q.empty())
    {
        tc=q.front();
        q.pop();
        for (i=0; i<4; i++)
        {
            ttc.x=tc.x+dir_left[i][0];
            ttc.y=tc.y+dir_left[i][1];
            if (judge(ttc))
            {
                if (v[tc.x][tc.y]+1 < v[ttc.x][ttc.y])
                {
                    v[ttc.x][ttc.y]=v[tc.x][tc.y]+1;
                    q.push(ttc);
                }
            }
        }
    }
}
int main()
{
    int i,j,prob,scoor;
    char tc;
    scanf("%d",&prob);
    while (prob--)
    {
        scanf("%d%d",&w,&h);
        getchar();
        for (i=0; i<h; i++)
        {
            for (j=0; j<w; j++)
            {
                scanf("%c",&tc);
                if (tc == '#')
                    map[i][j]=8;
                else if (tc == '.')
                    map[i][j]=0;
                else if (tc == 'S')
                {
                    map[i][j]=1;
                    s.x=i;
                    s.y=j;
                }
                else
                {
                    map[i][j]=-1;
                    e.x=i;
                    e.y=j;
                }
            }
            getchar();
        }
        dl=0;
        dr=0;
        memset(v,0x3f,sizeof(v));
        BFS();
        printf("%d %d %d\n",DFS_Left(s,0)+1,DFS_Right(s,0)+1,v[e.x][e.y]);
    }

}