Submission #1184427

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184427		steveonalex	Colors (BOI20_colors)	C++20	22 / 100	2 ms	440 KiB

Colors

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(abs(a), abs(b));}
ll lcm(ll a, ll b){return abs(a) / gcd(a, b) * abs(b);}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

int solve(ll n);

// namespace InteractorLib{
//     set<ll> S;
//     ll last = 0;
//     ll c;
//     bool valid;

//     int query(ll x){
//         if (S.insert(x).second == false){
//             valid = false;
//         }
//         ll diff = abs(last - x);
//         last = x;
//         return diff >= c;
//     }

//     int grade(){
//         ll n = rngesus(1, 125);
//         c = rngesus(1, n);

//         S.clear(); last = 0;
//         valid = true;
        
//         ll ans = solve(n);

//         if (valid == false) return -1;
//         if (ans != c) return -1;
//         return S.size();
//     }
// };
// using namespace InteractorLib;

int query(ll x){
    cout << "? " << x << endl;
    int verdict; cin >> verdict;
    return verdict;
}

void update(pair<ll, ll> &p, ll x, bool verdict){
    if (verdict) minimize(p.second, x);
    else maximize(p.first, x + 1);
}

int solve(ll n){
    pair<ll, ll> ans = make_pair(1, n);
    ll last = -1;

    if (n <= 64){
        ll l = 1, r = n;
        while(l <= r){
            int verdict = query(l);
            if (last != -1) update(ans, abs(last - l), verdict);
            last = l++;

            if (l <= r){
                verdict = query(r);
                update(ans, abs(last - r), verdict);
                last = r--;
            }
        }
    }
    else{
        ll l = 32, r = n - 32 + 1;
        query(l);
        int verdict = query(r);
        update(ans, abs(r - l), verdict);

        last = r;

        if (verdict){
            l++; r--;
            while(l <= r){
                int verdict = query(l);
                update(ans, abs(last - l), verdict);
                last = l++;

                if (l <= r){
                    verdict = query(r);
                    update(ans, abs(last - r), verdict);
                    last = r--;
                }
            }
        }
        else{
            l--; r++;
            while(l > 0){
                int verdict = query(l);
                update(ans, abs(last - l), verdict);
                last = l--;

                verdict = query(r);
                update(ans, abs(last - r), verdict);
                last = r++;
            }
        }
    }

    return ans.first;
}

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);

    clock_t start = clock();

    // for(int t = 0; t <= 1000; ++t) cout << grade() << "\n";

    ll n; cin >> n;
    int ans = solve(n);
    cout << "= " << ans << endl;

    cerr << "Time elapsed: " << clock() - start << "ms!\n";
    return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 33