1 #include<cstdio>
2 #include<cstring>
3 #include<cstdlib>
4 #include<cmath>
5 #include<algorithm>
6 #define MAXN 5010
7 #define EPS 1e-8
8 using namespace std;
9 struct Line
10 {
11 double left,right,high;
12 int flag;
13 };
14 struct node
15 {
16 int cover;
17 double one,more;
18 };
19 node tree[MAXN<<2];
20 Line p[MAXN];
21 double x[MAXN];
22 int cmp1(const void *a,const void *b)
23 {
24 return (*(Line *)a).high>(*(Line *)b).high?1:-1;
25 }
26 int cmp2(const void *a,const void *b)
27 {
28 return *(double *)a>*(double *)b?1:-1;
29 }
30 inline int dbcmp(double s,double t)
31 {
32 if(fabs(s-t)<EPS)
33 return 0;
34 return s>t?1:-1;
35 }
36 int Bin(double val,int low,int high)
37 {
38 int mid,temp;
39 while(low<high)
40 {
41 mid=(low+high)>>1;
42 temp=dbcmp(x[mid],val);
43 if(temp==0)
44 return mid;
45 if(temp>0)
46 high=mid;
47 else
48 low=mid+1;
49 }
50 }
51 inline void PushUp(int L,int R,int rt)
52 {
53 if(tree[rt].cover>1)
54 tree[rt].one=tree[rt].more=x[R+1]-x[L];
55 else if(tree[rt].cover==1)
56 {
57 tree[rt].one=x[R+1]-x[L];
58 if(L==R)
59 tree[rt].more=0;
60 else
61 tree[rt].more=tree[rt<<1].one+tree[rt<<1|1].one;
62 }
63 else
64 {
65 if(L==R)
66 tree[rt].more=tree[rt].one=0;
67 else
68 {
69 tree[rt].one=tree[rt<<1].one+tree[rt<<1|1].one;
70 tree[rt].more=tree[rt<<1].more+tree[rt<<1|1].more;
71 }
72 }
73 }
74 void Update(int s,int t,int val,int L,int R,int rt)
75 {
76 if(s<=L&&R<=t)
77 {
78 tree[rt].cover+=val;
79 PushUp(L,R,rt);
80 }
81 else
82 {
83 int mid=(L+R)>>1;
84 if(mid>=s)
85 Update(s,t,val,L,mid,rt<<1);
86 if(t>mid)
87 Update(s,t,val,mid+1,R,rt<<1|1);
88 PushUp(L,R,rt);
89 }
90 }
91 int main()
92 {
93 double ans,x1,y1,x2,y2;
94 int n,i,c,cnt,m,s,t;
95 scanf("%d",&c);
96 while(c--)
97 {
98 scanf("%d",&n);
99 for(i=cnt=0;i<n;i++)
100 {
101 scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
102 if(dbcmp(x1,x2)==0||dbcmp(y1,y2)==0)
103 continue;
104 if(x1>x2)
105 swap(x1,x2);
106 if(y1>y2)
107 swap(y1,y2);
108 p[cnt].flag=1;
109 p[cnt].left=x1;
110 p[cnt].right=x2;
111 x[cnt]=x1;
112 p[cnt++].high=y1;
113 p[cnt].flag=-1;
114 p[cnt].left=x1;
115 p[cnt].right=x2;
116 x[cnt]=x2;
117 p[cnt++].high=y2;
118 }
119 qsort(p,cnt,sizeof(p[0]),cmp1);
120 qsort(x,cnt,sizeof(x[0]),cmp2);
121 for(i=m=0;i<cnt;i++)
122 {
123 if(dbcmp(x[m],x[i]))
124 x[++m]=x[i];
125 }
126 m++;
127 memset(tree,0,sizeof(tree));
128 for(ans=i=0;i<cnt-1;i++)
129 {
130 s=Bin(p[i].left,0,m);
131 t=Bin(p[i].right,0,m);
132 Update(s,t-1,p[i].flag,0,m-2,1);
133 ans+=(p[i+1].high-p[i].high)*tree[1].more;
134 }
135 printf("%.2lf\n",ans);
136 }
137 return 0;
138 }
