HDU4325--Flowers--树状数组,离散化
Description
As is known to all, the blooming time and duration varies between different kinds of flowers. Now there is a garden planted full of flowers. The gardener wants to know how many flowers will bloom in the garden in a specific time. But there are too many flowers in the garden, so he wants you to help him.
Input
The first line contains a single integer t (1 <= t <= 10), the number of test cases.
For each case, the first line contains two integer N and M, where N (1 <= N <= 10^5) is the number of flowers, and M (1 <= M <= 10^5) is the query times.
In the next N lines, each line contains two integer S i and T i (1 <= S i <= T i <= 10^9), means i-th flower will be blooming at time [S i, T i].
In the next M lines, each line contains an integer T i, means the time of i-th query.
Output
For each case, output the case number as shown and then print M lines. Each line contains an integer, meaning the number of blooming flowers.
Sample outputs are available for more details.
Sample Input
2
1 1
5 10
4
2 3
1 4
4 8
1
4
6
Sample Output
Case #1:
0
Case #2:
1
2
1
很简单的一道树状数组的改段求点的模版题,基本思想是:tree[]为树状数组,N个元素,tree[i]存放的是i至N被加了多少,
所以,修改[l,r]区间值的操作就变为了,
update(l,1);
update(r+1,-1);
查询某点的操作就变为了查询此点的前缀和
需要注意的是,此题目的数据范围太大,需要进行离散化1 <= S i <= T i <= 10^9
(关于离散化,会再写一篇博客) ```c++ #include
