Chat Ban.cpp

// https://codeforces.com/contest/1612/problem/C
/*

     ░██████╗██████╗░░█████╗░██████╗░░██████╗██╗░░██╗  ░██████╗░██╗░░░██╗██████╗░████████╗░█████╗░
     ██╔════╝██╔══██╗██╔══██╗██╔══██╗██╔════╝██║░░██║  ██╔════╝░██║░░░██║██╔══██╗╚══██╔══╝██╔══██╗
     ╚█████╗░██████╔╝███████║██████╔╝╚█████╗░███████║  ██║░░██╗░██║░░░██║██████╔╝░░░██║░░░███████║
     ░╚═══██╗██╔═══╝░██╔══██║██╔══██╗░╚═══██╗██╔══██║  ██║░░╚██╗██║░░░██║██╔═══╝░░░░██║░░░██╔══██║
     ██████╔╝██║░░░░░██║░░██║██║░░██║██████╔╝██║░░██║  ╚██████╔╝╚██████╔╝██║░░░░░░░░██║░░░██║░░██║
     ╚═════╝░╚═╝░░░░░╚═╝░░╚═╝╚═╝░░╚═╝╚═════╝░╚═╝░░╚═╝  ░╚═════╝░░╚═════╝░╚═╝░░░░░░░░╚═╝░░░╚═╝░░╚═╝
    ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
    █████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗█████╗
    ╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝╚════╝
    ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░

*/

#include <bits/stdc++.h>

using namespace std;

#define fi          first
#define se          second
#define pb          push_back
#define mp          make_pair
#define all(x)      x.begin(), x.end()
#define ll          long long
#define pll         pair<ll, ll>
#define vll         vector<long long>
#define mll         map<ll, ll>
#define inf         1e18
#define gcd(a, b)   __gcd(a, b)
#define range(a,b)  substr(a,b-a+1)
#define setbits(x)  __builtin_popcountll(x)
#define zrobits(x)  __builtin_ctzll(x)
#define fori(a, n)  for (ll i = a; i < n; i++)
#define forj(a, n)  for (ll j = a; j < n; j++)
#define fork(a, n)  for (ll k = a; k < n; k++)
#define print(x)    for (auto i : x) {cout << i << " ";}
#define FIO         ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
mt19937             rng(chrono::steady_clock::now().time_since_epoch().count());

template <class T>
bool comp(T a, T b) {
    if (a < b)
        return true;
    return false;
}

int main()
{
    FIO;

    #ifndef ONLINE_JUDGE
    //remove this piece of code when this has to be submitted in kickstart, coding ninjas
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    //freopen is used to associate a file with stdin or stdout stream in C++
    #endif

    ll t;
    cin >> t;
    while (t--) {
        ll k, x;
        cin >> k >> x;
        if (x >= (k * (k + 1)) / 2 + ((k - 1) * k) / 2)
            cout << 2 * k - 1 << "\n";
        else if (x > (k * (k + 1)) / 2) {
            ll prev = (k * (k + 1)) / 2;
            ll l = 1, r = k - 1;
            while (l <= r) {
                ll mid = (l + r) / 2;
                if (x > prev + (mid * (2 * k - mid - 1)) / 2)
                    l = mid + 1;
                else
                    r = mid - 1;
            }
            cout << l + k << "\n";
        }
        else {
            ll l = 1, r = k;
            while (l <= r) {
                ll mid = (l + r) / 2;
                if (x > (mid * (mid + 1)) / 2)
                    l = mid + 1;
                else
                    r = mid - 1;
            }
            cout << l << "\n";
        }
    }

    return 0;
}