A962.Square Pasture--Bronze

普及-

USACO

通过率:0%

时间限制:1.00s

内存限制:128MB

题目描述

Farmer John's largest pasture can be regarded as a large 2D grid of square
"cells" (picture a huge chess board). Currently, there are NN cows occupying
some of these cells (1N2001 \leq N \leq 200).
Farmer John wants to build a fence that will enclose a square region of cells;
the square must be oriented so its sides are parallel with the xx and yy
axes, and it could be as small as a single cell. Please help him count the
number of distinct subsets of cows that he can enclose in such a region. Note
that the empty subset should be counted as one of these.

输入格式

The first line contains a single integer NN. Each of the next NN lines Each
of the next NN lines contains two space-separated integers, indicating the
(x,y)(x,y) coordinates of a cow's cell. All xx coordinates are distinct from
each-other, and all yy coordinates are distinct from each-other. All xx and
yy values lie in the range 01090 \ldots 10^9.
Note that although the coordinates of cells with cows are nonnegative, the
square fenced area might possibly extend into cells with negative coordinates.

输出格式

The number of subsets of cows that FJ can fence off. It can be shown that this
quantity fits within a signed 32-bit integer.

输入输出样例

  • 输入#1

    4
    0 2
    2 3
    3 1
    1 0
    

    输出#1

    14
    

说明/提示

In this example, there are 242^4 subsets in total. FJ cannot create a fence
enclosing only cows 1 and 3, or only cows 2 and 4, so the answer is
242=162=142^4-2=16-2=14.

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