Playlist CSES Problem Set Solution | Cses sorting and searching problem solution

 Playlist CSES Problem Set Solution- 

playlist cses problems solution with code and explanation.

Problem statement- 

• Time limit: 1.00 s
 
• Memory limit: 512 MB

You are given a playlist of a radio station since its establishment. The playlist has a total of n$n$ songs.

What is the longest sequence of successive songs where each song is unique?

Input

The first input line contains an integer n$n$: the number of songs.

The next line has n$n$ integers k1,k2,…,kn$k_1,k_2,\dots ,k_n$: the id number of each song.

Output

Print the length of the longest sequence of unique songs.

Constraints

• 1≤n≤2⋅105$1\le n\le 2\cdot {10}^5$
  
• 1≤ki≤109$1\le k_i\le {10}^9$
  

Example

Input:
8
1 2 1 3 2 7 4 2

Output:
5







Solution-

this problem can be solved in O(1) time.You should follow the following step 

take input in a vector.

make two iterator i and j 

check weather ith song is already played or not if not insert it into map and update max if max<currans.

If ith song  already  played remove all element till ith element form map and update currans value as currans=(i-j);.

Follow code below-