Codeforces Round 621 (Div. 1 + Div. 2)
E
Cow and Treats
Codeforces
2500
原题
← DF →
翻译中…

After a successful year of milk production, Farmer John is rewarding his cows with their favorite treat: tasty grass!

翻译中…

On the field, there is a row of $n$ units of grass, each with a sweetness $s_i$. Farmer John has $m$ cows, each with a favorite sweetness $f_i$ and a hunger value $h_i$. He would like to pick two disjoint subsets of cows to line up on the left and right side of the grass row. There is no restriction on how many cows must be on either side. The cows will be treated in the following manner:

翻译中…
  • The cows from the left and right side will take turns feeding in an order decided by Farmer John.
  • When a cow feeds, it walks towards the other end without changing direction and eats grass of its favorite sweetness until it eats $h_i$ units.
  • The moment a cow eats $h_i$ units, it will fall asleep there, preventing further cows from passing it from both directions.
  • If it encounters another sleeping cow or reaches the end of the grass row, it will get upset. Farmer John absolutely does not want any cows to get upset.
翻译中…

Note that grass does not grow back. Also, to prevent cows from getting upset, not every cow has to feed since FJ can choose a subset of them.

翻译中…

Surprisingly, FJ has determined that sleeping cows are the most satisfied. If FJ orders optimally, what is the maximum number of sleeping cows that can result, and how many ways can FJ choose the subset of cows on the left and right side to achieve that maximum number of sleeping cows (modulo $10^9+7$)? The order in which FJ sends the cows does not matter as long as no cows get upset.

翻译中…

Input

翻译中…

The first line contains two integers $n$ and $m$ ($1 \le n \le 5000$, $1 \le m \le 5000$)  — the number of units of grass and the number of cows.

翻译中…

The second line contains $n$ integers $s_1, s_2, \ldots, s_n$ ($1 \le s_i \le n$)  — the sweetness values of the grass.

翻译中…

The $i$-th of the following $m$ lines contains two integers $f_i$ and $h_i$ ($1 \le f_i, h_i \le n$)  — the favorite sweetness and hunger value of the $i$-th cow. No two cows have the same hunger and favorite sweetness simultaneously.

翻译中…

Output

翻译中…

Output two integers  — the maximum number of sleeping cows that can result and the number of ways modulo $10^9+7$.

翻译中…

Note

翻译中…

In the first example, FJ can line up the cows as follows to achieve $2$ sleeping cows:

翻译中…
  • Cow $1$ is lined up on the left side and cow $2$ is lined up on the right side.
  • Cow $2$ is lined up on the left side and cow $1$ is lined up on the right side.
翻译中…

In the second example, FJ can line up the cows as follows to achieve $1$ sleeping cow:

翻译中…
  • Cow $1$ is lined up on the left side.
  • Cow $2$ is lined up on the left side.
  • Cow $1$ is lined up on the right side.
  • Cow $2$ is lined up on the right side.
翻译中…

In the third example, FJ can line up the cows as follows to achieve $2$ sleeping cows:

翻译中…
  • Cow $1$ and $2$ are lined up on the left side.
  • Cow $1$ and $2$ are lined up on the right side.
  • Cow $1$ is lined up on the left side and cow $2$ is lined up on the right side.
  • Cow $1$ is lined up on the right side and cow $2$ is lined up on the left side.
翻译中…

In the fourth example, FJ cannot end up with any sleeping cows, so there will be no cows lined up on either side.

翻译中…

样例

Input #1
5 2
1 1 1 1 1
1 2
1 3
Output #1
2 2
InputCopy OutputCopy
Input #2
5 2
1 1 1 1 1
1 2
1 4
Output #2
1 4
InputCopy OutputCopy
Input #3
3 2
2 3 2
3 1
2 1
Output #3
2 4
InputCopy OutputCopy
Input #4
5 1
1 1 1 1 1
2 5
Output #4
0 1
InputCopy OutputCopy
题目信息
题号
1307E
时间限制
1 s
内存限制
256 MB
标签
二分
组合数学
动态规划
贪心
模拟
数学

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