1 /*
2 线段树+扫描线+离散化
3 求多个矩形的面积
4 */
5 #include<stdio.h>
6 #include<string.h>
7 #include<stdlib.h>
8 #include<algorithm>
9 #include<iostream>
10 #include<queue>
11 #include<stack>
12 #include<math.h>
13 #include<map>
14 using namespace std;
15 const int maxn = 105;
16 const int maxm = 210;
17 struct SegTree{
18 int l,r;
19 int cover;
20 double L_val,R_val;
21 double sum;
22 }ST[ maxm<<2 ];
23 struct Line{
24 double x,y1,y2;
25 bool InOut;
26 }yLine[ maxm ];
27 int cmp( Line a,Line b ){
28 return a.x<b.x;
29 }
30 double yIndex[ maxm ];
31 int GetIndex( double val,int cnt ){
32 return lower_bound( yIndex,yIndex+cnt,val )-yIndex;
33 }
34
35 void build( int L,int R,int n ){
36 ST[ n ].l = L;
37 ST[ n ].r = R;
38 ST[ n ].cover = 0;
39 ST[ n ].sum = 0;
40 ST[ n ].L_val = yIndex[ L ];
41 ST[ n ].R_val = yIndex[ R ];
42 if( R-L>1 ){
43 int mid = (L+R)/2;
44 build( L,mid,2*n );
45 build( mid,R,2*n+1 );
46 }
47 }
48 void PushUp( int n ){
49 if( ST[ n ].cover>0 ){
50 ST[ n ].sum = ST[ n ].R_val-ST[ n ].L_val;
51 }
52 else if( ST[ n ].r-ST[ n ].l>1 ){
53 ST[ n ].sum = ST[ 2*n ].sum+ST[ 2*n+1 ].sum;
54 }
55 else
56 ST[ n ].sum = 0;
57 }
58 void update( int left,int right,bool InOut,int n ){
59 if( left==ST[ n ].l&&right==ST[ n ].r ){
60 if( InOut==true ){
61 ST[ n ].cover++;
62 }
63 else{
64 ST[ n ].cover--;
65 }
66 }
67 else {
68 int mid = (ST[ n ].l+ST[ n ].r)/2;
69 if( mid>=right ) update( left,right,InOut,2*n );
70 else if( mid<=left ) update( left,right,InOut,2*n+1 );
71 else {
72 update( left,mid,InOut,2*n );
73 update( mid,right,InOut,2*n+1 );
74 }
75 }
76 PushUp( n );
77 }
78
79 int main(){
80 int n;
81 int T = 1;
82 while( scanf("%d",&n)==1,n ){
83 printf("Test case #%d\n",T++);
84 double x1,y1,x2,y2;
85 int cnt = 0;
86 for( int i=0;i<n;i++ ){
87 scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
88 yLine[ 2*i ].x = x1;
89 yLine[ 2*i+1 ].x = x2;
90 yLine[ 2*i ].y1 = yLine[ 2*i+1 ].y1 = y1;
91 yLine[ 2*i ].y2 = yLine[ 2*i+1 ].y2 = y2;
92 yLine[ 2*i ].InOut = true;
93 yLine[ 2*i+1 ].InOut = false;
94 yIndex[ 2*i ] = y1;
95 yIndex[ 2*i+1 ] = y2;
96 }
97 sort( yLine,yLine+2*n,cmp );
98 sort( yIndex,yIndex+2*n );
99 for( int i=1;i<2*n;i++ ){
100 if( yIndex[i]!=yIndex[i-1] )
101 yIndex[ cnt++ ] = yIndex[ i-1 ];
102 }
103 yIndex[ cnt++ ] = yIndex[ 2*n-1 ];
104 build( 0,cnt-1,1 );
105 double res = 0;
106 update( GetIndex( yLine[0].y1,cnt ),GetIndex( yLine[0].y2,cnt ),yLine[0].InOut,1 );
107 for( int i=1;i<2*n;i++ ){
108 res += ST[ 1 ].sum*( yLine[i].x-yLine[i-1].x );
109 update( GetIndex( yLine[i].y1,cnt ),GetIndex( yLine[i].y2,cnt ),yLine[i].InOut,1 );
110 }
111 printf("Total explored area: %.2lf\n\n",res);
112 }
113 return 0;
114 }
