1119A - Ilya and a Colorful Walk - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin >> n;
    vector<int> arr(n);
    for (int i = 0; i < n; ++i)
        cin >> arr[i];
    int x1 = -1, x2 = -1;
    for (int i = 0; i < n - 1; ++i)
    {
        if (arr[i] != arr[n - 1])
        {
            x1 = n - 1 - i;
            break;
        }
    }
    for (int i = n - 1; i > 0; --i)
    {
        if (arr[i] != arr[0])
        {
            x2 = i;
            break;
        }
    }
    // cout<<x1<<" "<<x2<<endl;
    cout << max(x1, x2) << endl;
}