Mahmoud and Ehab and the final stage

5000ms

524288K

Description:

Mahmoud and Ehab solved Dr. Evil's questions so he gave them the password of the door of the evil land. When they tried to open the door using it, the door gave them a final question to solve before they leave (yes, the door is digital, Dr. Evil is modern). If they don't solve it, all the work will be useless and they won't leave the evil land forever. Will you help them?

Mahmoud and Ehab are given n strings s₁, s₂, ... , s_n numbered from 1 to n and q queries, Each query has one of the following forms:

1 a b (1 ≤ a ≤ b ≤ n), For all the intervals [l;r] where (a ≤ l ≤ r ≤ b) find the maximum value of this expression:
(r - l + 1) * LCP(s_l, s_l + 1, ... , s_r - 1, s_r) where LCP(str₁, str₂, str₃, ... ) is the length of the longest common prefix of the strings str₁, str₂, str₃, ... .
2 x y (1 ≤ x ≤ n) where y is a string, consisting of lowercase English letters. Change the string at position x to y.

Input:

The first line of input contains 2 integers n and q (1 ≤ n ≤ 10⁵, 1 ≤ q ≤ 10⁵) – The number of strings and the number of queries, respectively.

The second line contains n strings str_i consisting of lowercase English letters.

The next q lines describe the queries and may have one of the 2 forms:

1 a b (1 ≤ a ≤ b ≤ n).
2 x y (1 ≤ x ≤ n), where y is a string consisting of lowercase English letters.

the total length of all strings in input won't exceed 10⁵

Output:

For each query of first type output its answer in a new line.

Sample Input:

5 9
mahmoud mahmoudbadawy drmahmoud drevil mahmoud
1 1 5
1 1 2
1 2 3
2 3 mahmoud
2 4 mahmoud
2 2 mahmouu
1 1 5
1 2 3
1 1 1

Sample Output:

Informação

Provedor Codeforces

Código CF862F