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题库练习 The Union of k-Segments

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A10072 | $The Union of k-Segments$

时间限制1s

内存限制256MB

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题目描述

You are given $n$ segments on the coordinate axis Ox and the number $k$ . The point is satisfied if it belongs to at least $k$ segments. Find the smallest (by the number of segments) set of segments on the coordinate axis Ox which contains all satisfied points and no others.

输入格式

The first line contains two integers $n$ and $k$ ( $1<=k<=n<=10^{6}$ ) — the number of segments and the value of $k$ . The next $n$ lines contain two integers $l_{i},r_{i}$ ( $-10^{9}<=l_{i}<=r_{i}<=10^{9}$ ) each — the endpoints of the $i$ -th segment. The segments can degenerate and intersect each other. The segments are given in arbitrary order.

输出格式

First line contains integer $m$ — the smallest number of segments. Next $m$ lines contain two integers $a_{j},b_{j}$ ( $a_{j}<=b_{j}$ ) — the ends of $j$ -th segment in the answer. The segments should be listed in the order from left to right.

输入输出样例

输入 #1

输出 #1

2
0 2
3 5

输入 #2

输出 #2

1
0 5

C++ 编辑器

输入

输出