【坐标离散化】AOJ0531- Paint Color

  1 #include<iostream>
  2 #include<cstdio>
  3 #include<cstring>
  4 #include<cstdlib>
  5 #include<algorithm>
  6 #include<vector>
  7 #include<queue>
  8 using namespace std;
  9 int w,h,n,ans;
 10 const int MAXN=1000+10;
 11 int x1[MAXN],x2[MAXN],y1[MAXN],y2[MAXN];
 12 int hashx[MAXN*2],hashy[MAXN*2];
 13 int fld[MAXN*2][MAXN*2]; 
 14 int dx[4]={0,0,1,-1};
 15 int dy[4]={1,-1,0,0};
 16 
 17 void compress()
 18 {
 19     int tx=0,ty=0;
 20     for (int i=1;i<=n;i++)
 21     {
 22         hashx[++tx]=x1[i];hashx[++tx]=x2[i];
 23         hashy[++ty]=y1[i];hashy[++ty]=y2[i];
 24     }
 25     hashx[++tx]=0;hashx[++tx]=w;
 26     hashy[++ty]=0;hashy[++ty]=h;
 27     sort(hashx+1,hashx+tx+1);
 28     sort(hashy+1,hashy+ty+1);
 29     w=unique(hashx+1,hashx+tx+1)-(hashx+1);
 30     h=unique(hashy+1,hashy+ty+1)-(hashy+1);
 31     for (int i=1;i<=n;i++)
 32     {
 33         x1[i]=lower_bound(hashx+1,hashx+w+1,x1[i])-hashx-1;
 34         x2[i]=lower_bound(hashx+1,hashx+w+1,x2[i])-hashx-1;
 35         y1[i]=lower_bound(hashy+1,hashy+h+1,y1[i])-hashy-1;
 36         y2[i]=lower_bound(hashy+1,hashy+h+1,y2[i])-hashy-1;
 37     }
 38     w--;h--;
 39 }
 40 
 41 void init()
 42 {
 43     scanf("%d",&n);
 44     for (int i=1;i<=n;i++)
 45         scanf("%d%d%d%d",&x1[i],&y1[i],&x2[i],&y2[i]);
 46     compress();
 47 }
 48 
 49 void imos()    /*imos?*/
 50 {
 51     memset(fld,0,sizeof(fld));
 52     for (int i=1;i<=n;i++)
 53     {
 54         fld[x1[i]][y1[i]]++;
 55         fld[x2[i]][y2[i]]++;
 56         fld[x1[i]][y2[i]]--;
 57         fld[x2[i]][y1[i]]--;
 58     }
 59     
 60     for (int i=0;i<w;i++)
 61         for (int j=1;j<h;j++)
 62             fld[i][j]+=fld[i][j-1];
 63             
 64     for (int j=0;j<h;j++)
 65         for (int i=1;i<w;i++)
 66             fld[i][j]+=fld[i-1][j];
 67 }
 68 
 69 void bfs(int x,int y)
 70 {
 71     ans++;
 72     queue<int> qx,qy;
 73     qx.push(x);
 74     qy.push(y);
 75     fld[x][y]=1;
 76     while (!qx.empty())
 77     {
 78         int xx=qx.front();qx.pop();
 79         int yy=qy.front();qy.pop();
 80         for (int i=0;i<4;i++)
 81         {
 82              int nx=xx+dx[i],ny=yy+dy[i];
 83              if (nx<0 || ny<0 || nx>w || ny>h || fld[nx][ny]>0) continue;
 84              qx.push(nx);
 85              qy.push(ny);
 86              fld[nx][ny]=1;
 87         }
 88     }
 89 }
 90 
 91 void solve()
 92 {
 93     ans=0;
 94     for (int i=0;i<w;i++)
 95         for (int j=0;j<h;j++)
 96             if (fld[i][j]==0) bfs(i,j);
 97     printf("%d\n",ans);
 98 }
 99 
100 int main()
101 {
102     //freopen("input.txt","r",stdin);
103     //freopen("output.txt","w",stdout);
104     while (~scanf("%d%d",&w,&h)&&w&&h)
105     {
106         init();
107         imos();
108         solve();
109     }
110     return 0;    
111 }