bzoj1382: [Baltic2001]Mars Maps 2011-12-20

Posted 2020-06-17

1382: [Baltic2001]Mars Maps

 

Time Limit: 5 Sec  Memory Limit: 64 MB

Submit: 85  Solved: 38

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Description

 

给出N个矩形,N<=10000.其坐标不超过10^9.求其面积并

Input

 

先给出一个数字N,代表有N个矩形. 接下来N行,每行四个数,代表矩形的坐标.

Output

 

输出面积并

Sample Input

 

2

 

10 10 20 20

 

15 15 25 30

Sample Output

 

225 

HINT

 

Source

 

 

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线段树求矩形面积并，同poj1151,坐标为实数，不需要离散化处理。

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  1 Program Stone;
  2 
  3 var i,j,k,n,m,lc,rc:longint;
  4 
  5     x1,y1,x2,y2:array[1..100000]of longint;
  6 
  7     s,p:array[0..200000]of longint;
  8 
  9     io:array[1..200000]of longint;
 10 
 11     ans:int64;
 12 
 13     b:array[1..500000]of longint;
 14 
 15     a:array[1..500000]of int64;
 16 
 17  procedure kp(t,w:longint);
 18 
 19  var i,j,l,k,mid:longint;
 20 
 21   begin
 22 
 23     i:=t;j:=w;mid:=s[(t+w)div 2];
 24 
 25     repeat
 26 
 27       while s[i]<mid do inc(i);
 28 
 29       while s[j]>mid do dec(j);
 30 
 31       if i<=j then begin
 32 
 33                      k:=s[i];s[i]:=s[j];s[j]:=k;
 34 
 35                      l:=io[i];io[i]:=io[j];io[j]:=l;
 36 
 37                      inc(i);dec(j);
 38 
 39                    end;
 40 
 41     until i>j;
 42 
 43     if i<w then kp(i,w);
 44 
 45     if j>t then kp(t,j);
 46 
 47   end;
 48 
 49  procedure upadd(head,tail,num:longint);
 50 
 51  var i,j,k:longint;
 52 
 53   begin
 54 
 55     if (lc<=head)and(tail<=rc) then begin
 56 
 57                                       a[num]:=p[tail]-p[head-1];
 58 
 59                                       inc(b[num]);
 60 
 61                                       exit;
 62 
 63                                     end;
 64 
 65     k:=(head+tail)div 2;
 66 
 67     if lc<=k then upadd(head,k,num*2);
 68 
 69     if k<rc then upadd(k+1,tail,num*2+1);
 70 
 71     a[num]:=a[num*2]+a[num*2+1];
 72 
 73     if b[num]>0 then a[num]:=p[tail]-p[head-1];
 74 
 75   end;
 76 
 77  procedure updel(head,tail,num:longint);
 78 
 79  var i,j,k:longint;
 80 
 81   begin
 82 
 83     if (lc<=head)and(tail<=rc) then begin
 84 
 85                                       dec(b[num]);
 86 
 87                                       if b[num]=0 then a[num]:=a[num*2]+a[num*2+1];
 88 
 89                                       exit;
 90 
 91                                     end;
 92 
 93     k:=(head+tail)div 2;
 94 
 95     if lc<=k then updel(head,k,num*2);
 96 
 97     if k<rc  then updel(k+1,tail,num*2+1);
 98 
 99     if b[num]=0 then a[num]:=a[num*2]+a[num*2+1];
100 
101   end;
102 
103  
104 
105  procedure init;
106 
107  var i,j,k:longint;
108 
109   begin
110 
111      readln(n);
112 
113      for i:=1 to n do
114 
115       begin
116 
117         readln(x1[i],y1[i],x2[i],y2[i]);
118 
119         s[i]:=y1[i];s[i+n]:=y2[i];
120 
121         io[i]:=i;io[i+n]:=i+n;
122 
123       end;
124 
125      kp(1,2*n);
126 
127      m:=1;y1[io[1]]:=1;
128 
129      for i:=2 to 2*n do
130 
131       begin
132 
133        if s[i]<>s[i-1] then begin
134 
135                              p[m]:=s[i]-s[i-1];
136 
137                              inc(m);
138 
139                             end;
140 
141        if io[i]>n then y2[io[i]-n]:=m
142 
143                   else y1[io[i]]:=m;
144 
145       end;
146 
147  
148 
149      for i:=2 to m do p[i]:=p[i]+p[i-1];
150 
151      for i:=1 to n do
152 
153       begin
154 
155         s[i]:=x1[i];s[i+n]:=x2[i];
156 
157         io[i]:=i;io[i+n]:=i+n;
158 
159       end;
160 
161      kp(1,2*n);
162 
163      ans:=0;
164 
165      for i:=1 to 2*n do
166 
167       begin
168 
169         if s[i]<>s[i-1] then ans:=ans+a[1]*(s[i]-s[i-1]);
170 
171         if io[i]>n then j:=io[i]-n else j:=io[i];
172 
173         lc:=y1[j];rc:=y2[j]-1;
174 
175         if io[i]<=n  then upadd(1,m,1)
176 
177                      else updel(1,m,1);
178 
179       end;
180 
181   end;
182 
183 begin
184 
185  assign(input,‘input.in‘);reset(input);
186 
187  assign(output,‘output.out‘);rewrite(output);
188 
189  init;
190 
191  writeln(ans);
192 
193  close(input);close(output);
194 
195 end.
196 
197