1066C - Books Queries - CodeForces Solution

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _print(x); cerr << endl;
#else
#define debug(x)
#endif
#define eb emplace_back
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define rep(i, n) for (int i = 0; i < n; ++i)
#define repone(i, n) for (int i = 1; i <= n; ++i)
#define reprange(i,a,b) for(int i=(a);i<=(b);++i)
#define si(x) scanf("%d",&x)
#define sl(x) scanf("%lld",&x)
#define ss(s) scanf("%s",&s)
#define pi(x) printf("%d\n",x)
#define pl(x) printf("%lld\n",x)
#define ps(s) printf("%s\n",s)
#define all(x) x.begin(),x.end()
#define sortall(x) sort(all(x))
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;
typedef long double lld;
const int mod = 1000000007;
const int MOD = 998244353;
const char nline = '\n';

void _print(ll t) {cerr << t;}
void _print(int t) {cerr << t;}
void _print(string t) {cerr << t;}
void _print(char t) {cerr << t;}
void _print(lld t) {cerr << t;}
void _print(double t) {cerr << t;}
void _print(ull t) {cerr << t;}

template <class T, class V> void _print(pair <T, V> p);
template <class T> void _print(vector <T> v);
template <class T> void _print(set <T> v);
template <class T, class V> void _print(map <T, V> v);
template <class T> void _print(multiset <T> v);
template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.fi); cerr << ","; _print(p.se); cerr << "}";}
template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
/*-------------------------------------------------------------------------------------------------------------------------------------------*/


void solve() {
    int q;
    cin >> q;
    vector<int> v(2e5 + 5, 0);
    int l = 0, r = 0;
    for (int i = 0; i < q; i++) {
        char c; cin >> c;
        int id; cin >> id;
        if (i == 0) {
            v[id] = l;
            l--;
            r++;
            continue;
        }
        if (c == 'L') {
            v[id] = l;
            l--;
        }
        else if (c == 'R') {
            v[id] = r;
            r++;
        }
        else {
            cout << min(abs(v[id] - l), abs(v[id] - r)) - 1 << nline;
        }
    }
}

int main()
{
#ifndef ONLINE_JUDGE
    freopen("Errorf.in", "w", stderr);
#endif
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    int t = 1;
    //cin >> t;
    for (ll i = 1; i <= t; i++) {
        //cout << "Case " << i << ": " ;
        solve();
    }
    return 0;
}