oj.uz

Submission #699194

# Submission time Handle Problem Language Result Execution time Memory
699194 2023-02-16T05:16:36 Z maomao90 Colors (BOI20_colors) C++17
0 / 100
 0 ms 208 KB 
// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h> 
using namespace std;

#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;

ll n;
vll qry;

inline bool ask(ll x) {
    cout << "? " << x << endl;
    bool r; cin >> r;
    return r;
}

int main() {
    cin >> n;
    ll lo = 1, hi = n, mid;
    while (lo < hi) {
        mid = lo + hi + 1 >> 1;
        cerr << ' ' << mid << '\n';
        qry.pb(mid);
        lo = mid;
    }
    qry.pop_back();
    ll lft = LINF, rht = -LINF;
    ll d = 0;
    REP (i, 0, SZ(qry)) {
        if (i & 1 ^ 1) {
            d -= qry[i];
        } else {
            d += qry[i];
        }
        mnto(lft, d);
        mxto(rht, d);
    }
    ll s = -lft + 1;
    assert(s + rht <= n);
    ask(s);
    lo = 1, hi = n;
    bool tog = 0;
    while (lo < hi) {
        mid = lo + hi + 1 >> 1;
        if (!tog) {
            s -= mid;
        } else {
            s += mid;
        }
        tog ^= 1;
        if (s < 1 || s > n) {
            break;
        }
        int res = ask(s);
        if (res) {
            lo = mid;
        } else {
            hi = mid - 1;
        }
    }
    assert(hi - lo <= 2);
    if (hi - lo == 2) {
        assert(hi == n);
        ask(1);
        if (ask(n)) {
            hi = n - 1;
        } else {
            hi = n;
        }
    }
    cout << "= " << hi << '\n';
    return 0;
}

Compilation message

Colors.cpp: In function 'int main()':
Colors.cpp:50:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   50 |         mid = lo + hi + 1 >> 1;
      |               ~~~~~~~~^~~
Colors.cpp:59:15: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   59 |         if (i & 1 ^ 1) {
      |             ~~^~~
Colors.cpp:73:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   73 |         mid = lo + hi + 1 >> 1;
      |               ~~~~~~~~^~~

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 208 KB Wrong guess
2 Halted 0 ms 0 KB -

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 208 KB Wrong guess
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 208 KB Wrong guess
2 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 208 KB Wrong guess
2 Halted 0 ms 0 KB -

Subtask #5
0 / 33.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 208 KB Wrong guess
2 Halted 0 ms 0 KB -