ural 1119 Metro

http://acm.timus.ru/problem.aspx?space=1&num=1119

 1 #include <cstdio>

 2 #include <cstring>

 3 #include <queue>

 4 #include <cmath>

 5 #include <algorithm>

 6 #define maxn 1010

 7 using namespace std;

 8 

 9 int head[maxn],e,n,m;

10 int dir[4][2]={{0,-1},{0,1},{1,0},{-1,0}};

11 bool vis[maxn][maxn];

12 bool visi[maxn][maxn];

13 double step;

14 

15 struct node

16 {

17     int x,y;

18     double step;

19 }st,st1,st2;

20 

21 void bfs(node st)

22 {

23     queue<node>q;

24     st.step=0.0;

25     q.push(st);

26     memset(visi,false,sizeof(visi));

27     visi[st.x][st.y]=true;

28     while(!q.empty())

29     {

30         st1=q.front();

31         q.pop();

32         if(st1.x==m&&st1.y==n) {step=st1.step;return;}

33         for(int i=0; i<4; i++)

34         {

35             int xx=st1.x+dir[i][0];

36             int yy=st1.y+dir[i][1];

37             if(xx>=0&&xx<=m&&yy>=0&&yy<=n&&!visi[xx][yy])

38             {

39                 st2.step=st1.step+100.0;

40                 visi[xx][yy]=true;

41                 st2.x=xx;

42                 st2.y=yy;

43                 q.push(st2);

44             }

45         }

46         if(vis[st1.x+1][st1.y+1]&&st1.x+1<=m&&st1.y+1<=n&&st1.x+1>=0&&st1.y+1>=0)

47         {

48             vis[st1.x+1][st1.y+1]=true;

49             st2.x=st1.x+1;

50             st2.y=st1.y+1;

51             st2.step=st1.step+sqrt(2)*100.0;

52             q.push(st2);

53         }

54     }

55 }

56 int main()

57 {

58     int k,a,b;

59     step=0;

60     scanf("%d%d",&n,&m);

61     scanf("%d",&k);

62     memset(vis,false,sizeof(vis));

63     for(int i=1; i<=k; i++)

64     {

65         scanf("%d%d",&a,&b);

66         vis[b][a]=true;

67     }

68     st.x=0;

69     st.y=0;

70     bfs(st);

71     printf("%.0lf\n",step);

72     return 0;

73 }

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