UVa221 Urban Elevations

暴力枚举判断是否可见。

注意特判几栋房子一起遮挡一栋房子的情况。

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<queue>
 6 using namespace std;
 7 const int mxn=1010;
 8 struct building{
 9     int x,y,w,h;
10     int id;
11 }a[mxn],b[mxn];
12 int cmp(const building c,const building d){
13     return (c.x<d.x)||(c.x==d.x && c.y<d.y);
14 }
15 int n,m;
16 bool check(int t){
17     int pos=a[t].x;
18     int cnt=0;
19     for(int i=1;i<=n;i++){
20         if(i==t)continue;
21         if(a[i].y<a[t].y && a[i].x<=a[t].x && a[i].x+a[i].w>=a[t].x+a[t].w && a[i].h>=a[t].h)return false;
22         if(a[i].y<a[t].y && a[i].h>=a[t].h && a[i].x<=pos && a[i].x+a[i].w>=pos)pos=max(pos,a[i].x+a[i].w);
23     if(pos<a[t].x+a[t].w)return true;
24     return false;
25 }
26 int ans[mxn],top=0;
27 void solve(){
28     for(int i=1;i<=n;i++)
29         if(check(i))ans[++top]=a[i].id;
30     return;
31 }
32 int main(){
33     int i,j;
34     int cas=0;
35     while(scanf("%d",&n) && n){
36         if(cas)printf("\n");
37         top=0;
38         for(i=1;i<=n;i++){
39             scanf("%d%d%d%*d%d",&a[i].x,&a[i].y,&a[i].w,&a[i].h);
40             a[i].id=i;
41         }
42         sort(a+1,a+n+1,cmp);
43         solve();
44         printf("For map #%d, the visible buildings are numbered as follows:\n",++cas);
45         for(i=1;i<top;i++)printf("%d ",ans[i]);
46         printf("%d",ans[top]);
47         printf("\n");
48     }
49     return 0;
50 }