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Deforestation

Time limit2sMemory limit2048 MB

Summary
Given N trees on a number line and K intervals that each must keep at least t trees, find the maximum number of trees that can be cut down.
Level

Medium6 of 10

Topics
Greedy, Sorting, Binary search, Union-find
Solved
No attempts yet

Problem

Farmer John is expanding his farm! He has identified the perfect location in the Red-Black Forest, which consists of NN trees (1≤N≤1051 \le N \le 10^5) on a number line, with the ii-th tree at position xix_i (−109≤xi≤109-10^9 \le x_i \le 10^9).

Environmental protection laws restrict which trees Farmer John can cut down to make space for his farm. There are KK restrictions (1≤K≤1051 \le K \le 10^5) specifying that there must always be at least tit_i trees (1≤ti≤N1 \le t_i \le N) in the line segment [li,ri][l_i, r_i], including the endpoints (−109≤li≤ri≤109-10^9 \le l_i \le r_i \le 10^9). It is guaranteed that the Red-Black Forest initially satisfies these restrictions.

Farmer John wants to make his farm as big as possible. Please help him compute the maximum number of trees he can cut down while still satisfying all the restrictions.

Input

Each input consists of TT (1≤T≤101 \le T \le 10) independent test cases. It is guaranteed that the sums of all NN and of all KK within an input each do not exceed 3⋅1053 \cdot 10^5.

The first line of input contains TT. Each test case is then formatted as follows:

The first line contains integers NN and KK.

The next line contains the NN integers x1,…,xNx_1, \dots, x_N.

Each of the next KK lines contains three space-separated integers: lil_i, rir_i and tit_i.

Output

For each test case, output a single line with an integer denoting the maximum number of trees Farmer John can cut down.

Hint

For the first test case, Farmer John can cut down the first 44 trees, leaving trees at xi=2,6,7x_i = 2, 6, 7 to satisfy the restriction.

For the second test case, the additional restriction does not affect which trees Farmer John can cut down, so he can cut down the same trees and satisfy both restrictions.

For the third test case, Farmer John can only cut down at most 33 trees because there are initially 77 trees but the second restriction requires him to leave at least 44 trees uncut.

Examples1

  1. Example 1

    Input
    3
    7 1
    8 4 10 1 2 6 7
    2 9 3
    7 2
    8 4 10 1 2 6 7
    2 9 3
    1 10 1
    7 2
    8 4 10 1 2 6 7
    2 9 3
    1 10 4
    
    Expected output
    4
    4
    3