Submission #1184069

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184069		steveonalex	Guess the number (BOI20_guess)	C++20	100 / 100	1 ms	436 KiB

Guess

#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());
    }

void solve(){
    int n; cin >> n;
    int l = 1, r = n;
    while(l <= r){
        int mid = (l + r) >> 1;
        cout << "? " << mid << endl;
        int verdict; cin >> verdict;
        if (verdict == 0){
            cout << "= " << mid << endl;
            return;
        }
        else if (verdict == -1) l = mid + 1;
        else r = mid - 1;
    }
}

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

    clock_t start = clock();

    solve();

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

• Subtask 1: 29 / 29
• Subtask 2: 71 / 71