longestarithmeticsubarraygooglekickstart1.cpp

#include <iostream>
using namespace std;
int main(){
    int n;
    cout << "Enter size: ";
    cin >> n;
    int a[n];
    for(int i=0;i<n;i++){
        cin >> a[i];
    }
    int ans = 2;
    int pd = a[1] - a[0];
    int j=2;
    int curr = 2;
    while(j<n){
        if(pd==a[j]-a[j-1]){
            curr++;
        }else{
            pd = a[j] - a[j-1];
            curr = 2;
        }
        ans = max(ans, curr);
        j++;
    }
    cout << ans << endl;
    return 0;
}