RoAlgo PreOJI 2024 VIII | egale

You can apply two types of operations on a sequence $x_1, x_2, \dots x_k$ of natural numbers:

1. Choose two numbers $(i, j)$ with $1 \leq i \leq j \leq k$ and set every value from $i$ to $j$ to $0$.
2. Choose two numbers $(i, j)$ with $1 \leq i \leq j \leq k$ and add $1$ to every value from $i$ to $j$.

For example, if we start with the sequence $x = [1, 3, 0, 2, 3]$, we could apply the following sequence of operations:

1. Apply operation 1 for $(2, 3)$. $x = [1, 0, 0, 2, 3]$.
2. Apply operation 2 for $(1, 3)$. $x = [2, 1, 1, 2, 3]$.
3. Apply operation 2 for $(4, 5)$. $x = [2, 1, 1, 3, 4]$.
4. Apply operation 1 for $(1, 3)$. $x = [0, 0, 0, 3, 4]$.

Task

Given $n$ and a sequence $a_1, a_2, \dots a_n$ of natural numbers. You are given $Q$ queries of the form $l, r, v$. What is the minimum number of operations needed to make $a_l = a_{l+1} = a_{l+2} = \dots = a_r = v$? After each query, the sequence $a$ will reset to its initial state.

Input data

The first line of the input file egale.in contains two integers, $n$ and $Q$. The second line contains the sequence $a_1, a_2, \dots a_n$ of natural numbers. The next $Q$ lines each contain a triplet $l, r, v$.

Output data

For each $i$ from $1$ to $Q$, the $i$-th line of the output file egale.out will contain a single integer, the answer to the $i$-th query.

Constraints and clarifications

• $1 \leq n, Q \leq 100\,000$
• $0 \leq a_i \leq 200$ for each $i$ from $1$ to $n$
• $1 \leq l \leq r \leq n$ and $0 \leq v \leq 200$ for each query

Example 1

egale.in

11 5
1 2 1 2 1 0 5 2 3 1 6
1 4 1
1 4 2
1 11 0
1 11 4
6 9 5

egale.out

2
2
1
5
6

Explanation

For the first query, we need to find the minimum number of operations to make all elements in the sequence $[1, 2, 1, 2]$ equal to $1$. The only way to do this in 2 operations is to apply operation 1 to the entire sequence, followed by operation 2 to the entire sequence.

Example 2

egale.in

10 10
3 2 9 4 10 9 1 0 8 6
3 3 7
4 5 9
5 8 9
1 6 3
5 5 7
3 10 2
3 4 1
7 8 5
3 8 10
4 7 1

egale.out

8
10
10
4
8
3
2
5
11
2

Example 3

egale.in

5 4
0 1 0 0 1 
1 1 0
1 2 0
1 3 0
3 4 0

egale.out

0
1
1
0

Explanation

This example checks $v = 0$ for each query.

For the first query, all elements are already $0$, so no operations are needed.

For the second query, we can apply operation 1 on the interval $(1, 2)$.