Physical Education Lessons

题意翻译

#### 题意： Alex高中毕业了，他现在是大学新生。虽然他学习编程，但他还是要上体育课，这对他来说完全是一个意外。快要期末了，但是不幸的Alex的体育学分还是零蛋！ Alex可不希望被开除，他想知道到期末还有多少天的工作日，这样他就能在这些日子里修体育学分。但是在这里计算工作日可不是件容易的事情： 从现在到学期结束还有 $n$ 天(从 $1$ 到 $n$ 编号)，他们一开始都是工作日。接下来学校的工作人员会**依次**发出 $q$ 个指令，每个指令可以用三个参数 $l,r,k$ 描述： - 如果 $k=1$，那么从 $l$ 到 $r$ （包含端点）的所有日子都变成**非**工作日。 - 如果 $k=2$，那么从 $l$ 到 $r$ （包含端点）的所有日子都变成**工作日**。 帮助Alex统计每个指令下发后，剩余的工作日天数。 #### 输入格式： 第一行一个整数 $n$，第二行一个整数 $q$ $(1\le n\le 10^9,\;1\le q\le 3\cdot 10^5)$，分别是剩余的天数和指令的个数。 接下来 $q$ 行，第 $i$ 行有 $3$ 个整数 $l_i,r_i,k_i$，描述第 $i$ 个指令 $(1\le l_i,r_i\le n,\;1\le k\le 2)$。 #### 输出格式： 输出 $q$ 行，第 $i$ 行表示第 $i$ 个指令被下发后剩余的工作日天数。 Translated by 小粉兔

题目描述

This year Alex has finished school, and now he is a first-year student of Berland State University. For him it was a total surprise that even though he studies programming, he still has to attend physical education lessons. The end of the term is very soon, but, unfortunately, Alex still hasn't attended a single lesson! Since Alex doesn't want to get expelled, he wants to know the number of working days left until the end of the term, so he can attend physical education lessons during these days. But in BSU calculating the number of working days is a complicated matter: There are $ n $ days left before the end of the term (numbered from $ 1 $ to $ n $ ), and initially all of them are working days. Then the university staff sequentially publishes $ q $ orders, one after another. Each order is characterised by three numbers $ l $ , $ r $ and $ k $ : - If $ k=1 $ , then all days from $ l $ to $ r $ (inclusive) become non-working days. If some of these days are made working days by some previous order, then these days still become non-working days; - If $ k=2 $ , then all days from $ l $ to $ r $ (inclusive) become working days. If some of these days are made non-working days by some previous order, then these days still become working days. Help Alex to determine the number of working days left after each order!

输入输出格式

输入格式

The first line contains one integer $ n $ , and the second line — one integer $ q $ ( $ 1<=n<=10^{9} $ , $ 1<=q<=3·10^{5} $ ) — the number of days left before the end of the term, and the number of orders, respectively. Then $ q $ lines follow, $ i $ -th line containing three integers $ l_{i} $ , $ r_{i} $ and $ k_{i} $ representing $ i $ -th order ( $ 1<=l_{i}<=r_{i}<=n $ , $ 1<=k_{i}<=2 $ ).

输出格式

Print $ q $ integers. $ i $ -th of them must be equal to the number of working days left until the end of the term after the first $ i $ orders are published.

输入输出样例

输入样例 #1

4
6
1 2 1
3 4 1
2 3 2
1 3 2
2 4 1
1 4 2

输出样例 #1

2
0
2
3
1
4