编程介的小学生 2019-12-27 22:30 采纳率: 20.5%
浏览 58

Binary Indexed Tree 是怎么做的

Problem Description
Recently, Mr. Frog has learned binary indexed tree. Here is the code of adding t to the interval [1,x]:

void add (int x, int t ){
    for (int i = x; i != 0; i -= i & (-i))
        a[i] += t;
}

If Mr. Frog is required to add t to the interval [l,r], he will add(r,t), and then add(l - 1,-t).

The cost of an interval [l,r] is defined as the number of the “really changed point”. The “really changed point” is the point whose value is modified by the given code.

For example, in order to add 1 to the interval [6,6], Mr. Frog will add 1 to the interval 1,6, and add -1 to the interval 1,5.

As the result, a[6] will be added by 1, a[5] will be added by -1, and a[4] will be added by 0. a[6] and a[5] are “really changed point”, and the cost is 2.

Mr. Frog wants to calculate the sum of the cost of the interval [l,r]⊆ [1,n] where l and r are two integers. Help Mr. Frog solve the problem.

Input
The first line contains only one integer T (T≤10000), which indicates the number of test cases.

For each test case, it contains an integer n (1≤n≤1018).

Output
For each test case, output one line ”Case #x: y”, where x is the case number (starting from 1), y is the sum of the cost (modulo 1000000007).

Sample Input
3
1
2
3

Sample Output
Case #1: 1
Case #2: 4
Case #3: 10

  • 写回答

0条回答 默认 最新

    报告相同问题?

    悬赏问题

    • ¥15 stata安慰剂检验作图但是真实值不出现在图上
    • ¥15 c程序不知道为什么得不到结果
    • ¥40 复杂的限制性的商函数处理
    • ¥15 程序不包含适用于入口点的静态Main方法
    • ¥15 素材场景中光线烘焙后灯光失效
    • ¥15 请教一下各位,为什么我这个没有实现模拟点击
    • ¥15 执行 virtuoso 命令后,界面没有,cadence 启动不起来
    • ¥50 comfyui下连接animatediff节点生成视频质量非常差的原因
    • ¥20 有关区间dp的问题求解
    • ¥15 多电路系统共用电源的串扰问题