Max_No.of_Cups.cpp

// /*
// In Turkey, an ice cream parlour gives an offer to a lucky kid.
// The parlour keeps N ice cream cups in a row, and there are different flavours 
// of icecreams, where i-th cup filled with the flavour[i] type of ice cream.

// The kid can pick the continuous set of ice cream cups, where the cups are filled
// with icecreams of utmost two different flavours. The kid wants to 
// pick the maximum number of ice cream cups from the row.

// You will be given the integer array, flavours[] of size N.
// Your task is to help the kid to pick the maximum number of ice cream cups 
// with at most two different flavours.


// Input Format:
// -------------
// Line-1: An integer, number of icecreams.
// Line-2: N space separated integers, flavours[] 

// Output Format:
// --------------
// Print an integer result, maximum number of icecream cups can be picked.


// Sample Input-1:
// ---------------
// 10
// 1 2 3 1 1 3 3 2 3 2

// Sample Output-1:
// ----------------
// 5

// Explanation:
// ------------
// The kid can pick the continuous set of icecream cups as follows: 3 1 1 3 3
// Where the cups are filled with two different flavours, 1 and 3.



// Sample Input-2:
// ---------------
// 10
// 2 1 1 3 2 1 3 0 0 3

// Sample Output-2:
// ----------------
// 4




#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    vector<int> v(n,0);
    for(int i=0;i<n;i++){
        cin>>v[i];
    }
    unordered_map<int,int> m;
    int maxi=INT_MIN;
    int j=0;
    for(int i=0;i<n;i++){
        m[v[i]]++;
        while(m.size()>2){
            m[v[j]]--;
            if(m[v[j]]==0){
                m.erase(v[j]);
            }
            j++;
        }
        maxi=max(maxi,i-j+1);
    }
    cout<<maxi;
}