HDU 4462 Scaring the Birds

枚举题。

最多只有10个vacant，所以把(1<<k)中使用vacant的情况都枚举出来找最小值就可以了。

具体看代码，不解释。

  1 #include<stdio.h>
  2 #include<iostream>
  3 using namespace std;
  4 
  5 #include<math.h>
  6 #include<stdlib.h>
  7 #include<algorithm>
  8 #include<string>
  9 #include<string.h>
 10 #include<map>
 11 #include<queue>
 12 #define repA(p,q,i)  for(int (i)=(p); (i)!=(q); ++(i) )
 13 #define repD(p,q,i)  for(int (i)=(p); (i)!=(q); --(i) )
 14 #define repAE(p,q,i)  for(int (i)=(p); (i)<=(q); ++(i) )
 15 #define repDE(p,q,i)  for(int (i)=(p); (i)>=(q); --(i) )
 16 #define range 52
 17 #define maxn 0x3f3f3f3f
 18 
 19 struct node{
 20     int x,y,r;
 21 };
 22 
 23 node vacant[11];
 24 int confirm[range][range];
 25 int n,k,LIM;
 26 
 27 void change(int loc);
 28 bool solve(int num, int &here);
 29 
 30 int main()
 31 {
 32     while( scanf("%d",&n) != EOF )
 33     {
 34         if(n==0)  break;
 35         repAE(1,n,i)
 36           repAE(1,n,j)
 37           confirm[i][j]=1;
 38         scanf("%d",&k);
 39         LIM = (1<<k);
 40         repA(0,k,i)
 41         {
 42           scanf("%d%d",&vacant[i].x,&vacant[i].y);
 43           confirm[vacant[i].x][vacant[i].y] = -1;
 44         }
 45         repA(0,k,i)
 46           scanf("%d",&vacant[i].r);
 47         
 48         int used = maxn ;
 49         int here;
 50         repA(0,LIM,num)
 51         {
 52             if( solve(num, here) )
 53               if( here < used )
 54               used = here;
 55         }
 56 
 57         if(used == maxn)  printf("-1\n");
 58         else printf("%d\n",used);
 59     }
 60     return 0;
 61 }
 62 
 63 bool solve(int num, int &here)
 64 {
 65     here=0;
 66     repAE(1,n,i)
 67       repAE(1,n,j)
 68       if(confirm[i][j] != -1)
 69       confirm[i][j] = 1;
 70     
 71     repA(0,k,i)
 72     {
 73         if(num & (1<<i) )
 74         {
 75             change(i);
 76             ++here;
 77         }
 78     }
 79 
 80     repAE(1,n,i)
 81       repAE(1,n,j)
 82       if(confirm[i][j] > 0)
 83       return false;
 84     
 85     return true;
 86 }
 87 
 88 void change(int loc)
 89 {
 90     int x = vacant[loc].x;
 91     int y = vacant[loc].y;
 92     int r = vacant[loc].r;
 93 
 94     int hang,lie,dis;
 95     for(hang=x; hang>0&&hang>=x-r; --hang)
 96     {
 97         dis = r - abs(hang - x) ;
 98         for(lie=max(1,y-dis); lie<=min(n,y+dis); ++lie)
 99           if(confirm[hang][lie] > 0)
100           confirm[hang][lie] = 0;
101     }
102     for(hang=x+1; hang<=n&&hang<=x+r; ++hang)
103     {
104         dis = r - abs(hang - x) ;
105         for(lie=max(1,y-dis); lie<=min(n,y+dis); ++lie)
106           if(confirm[hang][lie] > 0)
107           confirm[hang][lie] = 0;
108     }
109     return ;
110 }
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posted on 2013-10-15 19:52  码农之上~  阅读(220)  评论(0)  编辑  收藏  举报

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