HDU 1255

/*
扫描线求矩阵的覆盖面
离散化
线段树求面积并升级版
*/
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define lson (pos<<1)
#define rson (pos<<1|1)
typedef long long LL;
const int maxn = 10005;
int cnt,ret;
struct Seg{
    double a,b,h;
    int c;
    Seg(double a = 0,double b = 0,double h = 0,int c = 0):
        a(a),b(b),h(h),c(c){};
    friend bool operator < (Seg p,Seg q){
        return p.h < q.h;
    }
}seg[maxn];
double Hash[maxn];
int  HASH(double t){
    return lower_bound(Hash,Hash + ret,t) - Hash;
}
void Hash_init(){
   sort(Hash,Hash + ret);
   ret = unique(Hash,Hash + ret) - Hash;
}
struct Node{
    int l,r,col;
    double s,ss;
    int mid(){
        return (l + r) >> 1;
    }
    double len(){
        return Hash[r + 1] - Hash[l];
    }
}node[maxn << 2];
void build(int l,int r,int pos){
    node[pos].l = l;
    node[pos].r = r;
    node[pos].col = 0;
    node[pos].ss = node[pos].s = 0;
    if(l == r) return;
    int mid = node[pos].mid();
    build(l,mid,lson);
    build(mid + 1,r,rson);
}
void pushup(int pos){
    if(node[pos].col){
        node[pos].s = node[pos].len();
    }
    else if(node[pos]. l == node[pos].r){
        node[pos].s = 0;
    }
    else{
        node[pos].s = node[lson].s + node[rson].s;
    }
    if(node[pos].col > 1){
        node[pos].ss = node[pos].len();
    }
    else if(node[pos].l == node[pos].r){
        node[pos].ss = 0;
    }
    else if(node[pos].col == 1){
        node[pos].ss = node[lson].s + node[rson].s;
    }
    else{
        node[pos].ss = node[lson].ss + node[rson].ss;
    }
}
void update(int l,int r,int pos,int d){
    if(l <= node[pos].l && node[pos].r <= r){
        node[pos].col += d;
        pushup(pos);
        return;
    }
    int mid = node[pos].mid();
    if(l <= mid)
        update(l,r,lson,d);
    if(r  > mid)
        update(l,r,rson,d);
    pushup(pos);
}
int main(){
    int T,n;
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        cnt = 0;
        ret = 0;
        double a,b,c,d;
        for(int i = 0; i < n; i++){
            scanf("%lf%lf%lf%lf",&a,&b,&c,&d);
            seg[cnt++] = Seg(a,c,b,1);
            seg[cnt++] = Seg(a,c,d,-1);
            Hash[ret++] = a;
            Hash[ret++] = c;
        }
        Hash_init();
        sort(seg,seg + cnt);
        build(0,ret,1);
        double ans = 0;
        for(int i = 0; i < cnt - 1; i++){
            int l = HASH(seg[i].a),r = HASH(seg[i].b) - 1,c = seg[i].c;
            update(l,r,1,c);
            ans += node[1].ss * (seg[i + 1].h - seg[i].h);
        }
        printf("%.2f\n",ans);
    }
    return 0;
}
/*
1
2
0 0 1 1
0 0 1 1
*/