范围查询(Range)
Description
Let S be a set of n integral points on the x-axis. For each given interval [a, b], you are asked to count the points lying inside.
Input
The first line contains two integers: n (size of S) and m (the number of queries).
The second line enumerates all the n points in S.
Each of the following m lines consists of two integers a and b and defines an query interval [a, b].
Output
The number of points in S lying inside each of the m query intervals.
Example
Input
5 2
1 3 7 9 11
4 6
7 12
Output
0
3
Restrictions
0 <= n, m <= 5 * 10^5
For each query interval [a, b], it is guaranteed that a <= b.
Points in S are distinct from each other.
Coordinates of each point as well as the query interval boundaries a and b are non-negative integers not greater than 10^7.
Time: 2 sec
Memory: 256 MB
描述
数轴上有n个点，对于任一闭区间 [a, b]，试计算落在其内的点数。
输入
第一行包括两个整数：点的总数n，查询的次数m。
第二行包含n个数，为各个点的坐标。
以下m行，各包含两个整数：查询区间的左、右边界a和b。
输出
对每次查询，输出落在闭区间[a, b]内点的个数。
样例
见英文题面
限制
0 ≤ n, m ≤ 5×105
对于每次查询的区间[a, b]，都有a ≤ b
各点的坐标互异
各点的坐标、查询区间的边界a、b，均为不超过10^7的非负整数
时间：2 sec
内存：256 MB
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