1 #include<iostream> 2 #include<stdio.h> 3 #include<math.h> 4 #include<string.h> 5 #include<algorithm> 6 using namespace std; 7 #define re(i,n) for(int i=0;i<n;i++) 8 const int maxn=1e4+7; 9 const int mod=1e9+7; 10 typedef long long ll; 11 int x[maxn*2],y[maxn*2],xsz,ysz; 12 struct Node{ 13 int fy,ty; 14 int x; 15 int type; 16 }a[maxn*2]; 17 bool cmp(const Node&m,const Node&n){ 18 return m.x<n.x; 19 } 20 struct Data{ 21 int cnt,len; 22 }da[maxn*16]; 23 int fy,ty,type; 24 void insert(int id,int f,int t){ 25 //printf("inserting node %d ,from %d,to %d,fy %d ,ty %d,type %d ",id,y[f],y[t],fy,ty,type); 26 if(fy<=y[f]&&ty>=y[t]){ 27 da[id].cnt+=type; 28 if(da[id].cnt==0){ 29 if(f==t)da[id].len=0; 30 else da[id].len=da[id<<1].len+da[id<<1|1].len; 31 }else da[id].len=y[t]-y[f]; 32 return; 33 } 34 int mid=(f+t)>>1; 35 if(ty>y[mid])insert(id<<1|1,mid,t); 36 if(fy<y[mid])insert(id<<1,f,mid); 37 if(da[id].cnt==0)da[id].len=da[id<<1].len+da[id<<1|1].len; 38 else da[id].len=y[t]-y[f]; 39 } 40 int main(){ 41 int n; 42 while(cin>>n&&n){ 43 re(i,n){ 44 scanf("%d%d%d%d",&x[i*2],&y[i*2],&x[i*2+1],&y[i*2+1]); 45 a[i*2].fy=a[i*2+1].fy=min(y[i*2],y[i*2+1]); 46 a[i*2].ty=a[i*2+1].ty=max(y[i*2],y[i*2+1]); 47 a[i*2].x=min(x[i*2],x[i*2+1]); 48 a[i*2+1].x=max(x[i*2],x[i*2+1]); 49 a[i*2].type=1; 50 a[i*2+1].type=-1; 51 } 52 sort(y,y+n*2),ysz=unique(y,y+n*2)-y; 53 sort(a,a+n*2,cmp); 54 ll ans=0; 55 memset(da,0,sizeof(da)); 56 fy=a[0].fy,ty=a[0].ty,type=a[0].type; 57 insert(1,0,ysz-1); 58 //cout<<"The first time "<<da[1].cnt<<endl; 59 //cout<<"ans is "<<ans<<endl; 60 for(int i=1;i<n*2;i++){ 61 ans+=(ll)(a[i].x-a[i-1].x)*da[1].len; 62 ans%=mod; 63 fy=a[i].fy,ty=a[i].ty,type=a[i].type; 64 //printf("i=%d ans=%lld ",i,ans); 65 insert(1,0,ysz-1); 66 } 67 cout<<ans<<endl; 68 } 69 return 0; 70 }