Codeforces Round 583 (Div. 1 + Div. 2, based on Olympiad of Metropolises)
G
Feeling Good
Codeforces
3200
原题
← FH →
翻译中…

Recently biologists came to a fascinating conclusion about how to find a chameleon mood. Consider chameleon body to be a rectangular table $n \times m$, each cell of which may be green or blue and may change between these two colors. We will denote as $(x, y)$ ($1 \leq x \leq n$, $1 \leq y \leq m$) the cell in row $x$ and column $y$.

翻译中…

Let us define a chameleon good mood certificate to be four cells which are corners of some subrectangle of the table, such that colors in opposite cells among these four are similar, and at the same time not all of the four cell colors are similar. Formally, it is a group of four cells $(x_1, y_1)$, $(x_1, y_2)$, $(x_2, y_1)$, $(x_2, y_2)$ for some $1 \leq x_1 \lt x_2 \leq n$, $1 \leq y_1 \lt y_2 \leq m$, that colors of $(x_1, y_1)$ and $(x_2, y_2)$ coincide and colors of $(x_1, y_2)$ and $(x_2, y_1)$ coincide, but not all of the four cells share the same color. It was found that whenever such four cells are present, chameleon is in good mood, and vice versa: if there are no such four cells, chameleon is in bad mood.

翻译中…

You are asked to help scientists write a program determining the mood of chameleon. Let us consider that initially all cells of chameleon are green. After that chameleon coloring may change several times. On one change, colors of contiguous segment of some table row are replaced with the opposite. Formally, each color change is defined by three integers $a$, $l$, $r$ ($1 \leq a \leq n$, $1 \leq l \leq r \leq m$). On such change colors of all cells $(a, b)$ such that $l \leq b \leq r$ are replaced with the opposite.

翻译中…

Write a program that reports mood of the chameleon after each change. Additionally, if the chameleon mood is good, program should find out any four numbers $x_1$, $y_1$, $x_2$, $y_2$ such that four cells $(x_1, y_1)$, $(x_1, y_2)$, $(x_2, y_1)$, $(x_2, y_2)$ are the good mood certificate.

翻译中…

Input

翻译中…

The first line of input contains three integers $n$, $m$, $q$ ($1 \leq n, m \leq 2000$, $1 \leq q \leq 500\,000$), the sizes of the table and the number of changes respectively.

翻译中…

Each of the following $q$ lines contains 3 integers $a_i$, $l_i$, $r_i$ ($1 \leq a_i \leq n$, $1 \leq l_i \leq r_i \leq m$), describing $i$-th coloring change.

翻译中…

Output

翻译中…

Print $q$ lines. In the $i$-th line report the chameleon mood after first $i$ color changes for all $1 \leq i \leq q$.

翻译中…

If chameleon is in bad mood, print the only integer $-1$.

翻译中…

Otherwise, print four integers $x_1$, $y_1$, $x_2$, $y_2$ ($1 \leq x_1 \lt x_2 \leq n$, $1 \leq y_1 \lt y_2 \leq m$) such that four cells $(x_1, y_1)$, $(x_1, y_2)$, $(x_2, y_1)$, $(x_2, y_2)$ are the good mood certificate. If there are several ways to choose such four integers, print any valid one.

翻译中…

样例

Input #1
2 2 6
1 1 1
2 2 2
2 1 1
1 2 2
2 2 2
1 1 1
Output #1
-1
1 1 2 2
-1
-1
-1
1 1 2 2
InputCopy OutputCopy
Input #2
4 3 9
2 2 3
4 1 2
2 1 3
3 2 2
3 1 3
1 2 2
4 2 3
1 1 3
3 1 3
Output #2
-1
2 1 4 3
-1
2 1 3 2
3 2 4 3
1 1 2 2
1 1 2 2
-1
2 1 3 2
InputCopy OutputCopy
题目信息
题号
1214G
时间限制
3 s
内存限制
512 MB
标签
位运算
数据结构

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。