#5616. CSES2420 回文查询
0
CSES2420 回文查询
Palindrome Queries
You are given a string that consists of n characters between a–z. The positions of the string are indexed 1,2,\dots,n. Your task is to process m operations of the following types:
Change the character at position k to x
Check if the substring from position a to position b is a palindrome
Input
The first input line has two integers n and m: the length of the string and the number of operations. The next line has a string that consists of n characters. Finally, there are m lines that describe the operations. Each line is of the form "1 k x" or "2 a b".
Output
For each operation 2, print YES if the substring is a palindrome and NO otherwise.
Constraints
Example
Input
7 5
aybabtu
2 3 5
1 3 x
2 3 5
1 5 x
2 3 5
Output
YES
NO
YES