1 #include<cstdio>
2 #include<cstring>
3 #include<cstdlib>
4 #define MAXN 100010
5 struct Line
6 {
7 int left,right,high,flag;
8 };
9 struct node
10 {
11 int sum,cover;
12 };
13 Line p[MAXN];
14 node tree[MAXN<<2];
15 int x[MAXN];
16 inline bool Out(int x1,int y1,int x2,int y2)
17 {
18 return x1==-1&&y1==-1&&x2==-1&&y2==-1;
19 }
20 int cmp1(const void *a,const void *b)
21 {
22 return *(int *)a-*(int *)b;
23 }
24 int cmp2(const void *a,const void *b)
25 {
26 return (*(Line *)a).high-(*(Line *)b).high;
27 }
28 int Bin(int val,int low,int high)
29 {
30 int mid;
31 while(low<high)
32 {
33 mid=(low+high)>>1;
34 if(x[mid]==val)
35 return mid;
36 if(x[mid]<val)
37 low=mid+1;
38 else
39 high=mid;
40 }
41 }
42 void Build(int L,int R,int rt)
43 {
44 tree[rt].cover=tree[rt].sum=0;
45 if(L!=R)
46 {
47 int mid=(L+R)>>1;
48 Build(L,mid,rt<<1);
49 Build(mid+1,R,rt<<1|1);
50 }
51 }
52 inline void PushUp(int L,int R,int rt)
53 {
54 if(tree[rt].cover)
55 tree[rt].sum=x[R+1]-x[L];
56 else if(L==R)
57 tree[rt].sum=0;
58 else
59 tree[rt].sum=tree[rt<<1].sum+tree[rt<<1|1].sum;
60 }
61 void Update(int st,int en,int flag,int L,int R,int rt)
62 {
63 if(st<=L&&R<=en)
64 {
65 tree[rt].cover+=flag;
66 PushUp(L,R,rt);
67 }
68 else
69 {
70 int mid=(L+R)>>1;
71 if(mid>=st)
72 Update(st,en,flag,L,mid,rt<<1);
73 if(en>mid)
74 Update(st,en,flag,mid+1,R,rt<<1|1);
75 PushUp(L,R,rt);
76 }
77 }
78 int main()
79 {
80 int n,i,m,flag,x1,y1,x2,y2,ans,st,en;
81 for(n=flag=0;scanf("%d%d%d%d",&x1,&y1,&x2,&y2);)
82 {
83 if(Out(x1,y1,x2,y2))
84 flag++;
85 else
86 flag=0;
87 if(flag==2)
88 break;
89 if(flag)
90 {
91 qsort(x,n,sizeof(x[0]),cmp1);
92 qsort(p,n,sizeof(p[0]),cmp2);
93 for(i=m=0;i<n;i++)
94 {
95 if(x[i]!=x[m])
96 x[++m]=x[i];
97 }
98 Build(0,m-1,1);
99 for(i=ans=0;i<n-1;i++)
100 {
101 st=Bin(p[i].left,0,m+1);
102 en=Bin(p[i].right,0,m+1);
103 Update(st,en-1,p[i].flag,0,m-1,1);
104 ans+=(p[i+1].high-p[i].high)*tree[1].sum;
105 }
106 printf("%d\n",ans);
107 n=0;
108 }
109 else
110 {
111 x[n]=x1;
112 p[n].flag=1;
113 p[n].left=x1;
114 p[n].right=x2;
115 p[n++].high=y1;
116 x[n]=x2;
117 p[n].flag=-1;
118 p[n].left=x1;
119 p[n].right=x2;
120 p[n++].high=y2;
121 }
122 }
123 return 0;
124 }
