Distinct characters
Problem
You are given a string S of length N and there are Q queries. In each query, you are provided with 2 integers L and R. You need to find the number of distinct characters present in the range L to R.
Input :
- First line of Input contains N , length of string S.
- Second line of input contains string S containing lowercase alphabets only.
- Third line of Input contains Q , number of queries
- Each following Q lines contains 2 integers , L and R .
Output :
For each query , output number of distinct characters in newline .
Constraints :
- 1≤N≤105
- 1≤Q≤105
- 1≤L≤R≤N
Time Limit: 1.5
Memory Limit: 256
Source Limit:
Explanation
In the First Query , there are 5 distinct characters from substring 'nikunj ' .
In the Second Query , 4 there are 4 distinct characters from substring 'niku'.
