Имя: Пароль: Зарегистрироваться Восстановить пароль
07/12/2023 14:51:36

# Рабочее место участника

## Задачи

768. Nested Dolls

Ограничения: время – 3s/6s, память – 64MiB Ввод: input.txt или стандартный ввод Вывод: output.txt или стандартный вывод
Послать решение Blockly Посылки Темы Где Обсудить (0)

Dilworth is the world's most prominent collector of Russian nested dolls: he literally has thousands of them! You know, the wooden hollow dolls of different sizes of which the smallest doll is contained in the second smallest, and this doll is in turn contained in the next one and so forth. One day he wonders if there is another way of nesting them so he will end up with fewer nested dolls? After all, that would make his collection even more magnificent! He unpacks each nested doll and measures the width and height of each contained doll. A doll with width w_1 and height h_1 will fit in another doll of width w_2 and height h_2 if and only if w_1\ <\ w_2 and h_1\ <\ h_2. Can you help him calculate the smallest number of nested dolls possible to assemble from his massive list of measurements?
Input specifications
On the first line of input is a single positive integer 1\ ≤\ t\ ≤\ 20 specifying the number of test cases to follow. Each test case begins with a positive integer 1\ ≤\ m\ ≤\ 20000 on a line of itself telling the number of dolls in the test case. Next follow 2m positive integers w_1,\ h_1,\ w_2,\ h_2,\ …,\ w_m,\ h_m, where w_i is the width and h_i is the height of doll number i. 1\ ≤\ w_i,\ h_i\ ≤\ 10000 for all i.
Output specifications
For each test case there should be one line of output containing the minimum number of nested dolls possible

Sample input

4
3
20 30 40 50 30 40
4
20 30 10 10 30 20 40 50
3
10 30 20 20 30 10
4
10 10 20 30 40 50 39 51


Output for sample input

1
2
3
2

Source: Nordic CPC 2007