V Olimpiada Informatyczna 1997/1998
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Task: PRO
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Author: Wojciech Rytter
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III stage contest |
There are n rectangles drawn on the plane.
Each rectangle has sides parallel to the coordinate
axes and integer coordinates of vertices.
We define a block as follows:
The rectangles in Figure 1 form two separate blocks.
Figure 1
Write a program that:
In the first line of the input file PRO.IN there is an integer n, 1 <= n <=7000, which is the number of rectangles. In the following n lines there are coordinates of rectangles. Each rectangle is described by four numbers: coordinates x,y of the bottom-left vertex and coordinates x, y of the top-right vertex. All these coordinates are non-negative integers not greater than 10000.
In the first and only line of the file PRO.OUT there should be written a single integer - the number of separate blocks formed by the given rectangles.
ExampleFor the text file PRO.IN:
9 0 3 2 6 4 5 5 7 4 2 6 4 2 0 3 2 5 3 6 4 3 2 5 3 1 4 4 7 0 0 1 4 0 0 4 1the correct result is the text file PRO.OUT:
2