scu4445（模拟）

题目链接：https://vjudge.net/problem/SCU-4445

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<cmath>
 4 #include<algorithm>
 5 using namespace std;
 6 
 7 const int maxn=1010;
 8 const int inf=0x3f3f3f3f;
 9 
10 struct node
11 {
12     int x,y;
13 }po[maxn<<2];
14 
15 int main()
16 {
17     int n;
18     while(scanf("%d",&n)!=EOF)
19     {
20         for(int i=1;i<=n;i++)
21             scanf("%d%d",&po[i].x,&po[i].y);
22         int step=0;
23         int nowx=0,nowy=0;
24         int f=2;
25         while(step<=4*n+1)
26         {
27             int tx=-inf,ty=-inf;
28             if(f==1)
29             {
30                 for(int i=1;i<=n;i++)
31                     if(po[i].x==nowx&&po[i].y>nowy)
32                     {
33                         tx=po[i].x;
34                         if(ty!=-inf) ty=min(ty,po[i].y);
35                         else  ty=po[i].y;
36                     }
37 
38                 if(tx==-inf||ty==-inf) break;
39                 step++;
40                 nowx=tx;
41                 nowy=ty-1;
42                 f=2;
43             }
44             else if(f==2)
45             {
46                 for(int i=1;i<=n;i++)
47                     if(po[i].y==nowy&&po[i].x>nowx)
48                     {
49                         ty=po[i].y;
50                         if(tx!=-inf) tx=min(tx,po[i].x);
51                         else tx=po[i].x;
52                     }
53                     if(tx==-inf||ty==-inf) break;
54                     step++;
55                     nowx=tx-1;
56                     nowy=ty;
57                     f=3;
58 
59             }
60             else if(f==3)
61             {
62                 for(int i=1;i<=n;i++)
63                     if(po[i].x==nowx&&po[i].y<nowy)
64                     {
65                         tx=po[i].x;
66                         if(ty!=-inf) ty=max(ty,po[i].y);
67                         else ty=po[i].y;
68                     }
69                     if(tx==-inf||ty==-inf) break;
70                     step++;
71                     nowx=tx;
72                     nowy=ty+1;
73                     f=4;
74 
75             }
76             else
77             {
78                 for(int i=1;i<=n;i++)
79                     if(po[i].y==nowy&&po[i].x<nowx)
80                     {
81                         ty=po[i].y;
82                         if(tx!=-inf) tx=max(tx,po[i].x);
83                         else tx=po[i].x;
84                     }
85                     if(tx==-inf||ty==-inf) break;
86                     step++;
87                     nowx=tx+1;
88                     nowy=ty;
89                     f=1;
90 
91             }
92         }
93          if(step>4*n+1) puts("-1");
94             else printf("%d\n",step);
95     }
96     return 0;
97 
98 }

 

posted @ 2017-04-18 15:41  yijiull  阅读(117)  评论(0)  编辑  收藏  举报